diff --git a/Frameworks/Account/Account.swift b/Frameworks/Account/Account.swift
index 44b7d1e47..a32cad41d 100644
--- a/Frameworks/Account/Account.swift
+++ b/Frameworks/Account/Account.swift
@@ -642,45 +642,45 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 		}
 	}
 
-	public func fetchArticlesAsync(_ fetchType: FetchType, _ callback: @escaping ArticleSetBlock) {
+	public func fetchArticlesAsync(_ fetchType: FetchType, _ completion: @escaping ArticleSetBlock) {
 		switch fetchType {
 		case .starred:
-			fetchStarredArticlesAsync(callback)
+			fetchStarredArticlesAsync(completion)
 		case .unread:
-			fetchUnreadArticlesAsync(callback)
+			fetchUnreadArticlesAsync(completion)
 		case .today:
-			fetchTodayArticlesAsync(callback)
+			fetchTodayArticlesAsync(completion)
 		case .folder(let folder, let readFilter):
 			if readFilter {
-				return fetchUnreadArticlesAsync(folder: folder, callback)
+				return fetchUnreadArticlesAsync(folder: folder, completion)
 			} else {
-				return fetchArticlesAsync(folder: folder, callback)
+				return fetchArticlesAsync(folder: folder, completion)
 			}
 		case .webFeed(let webFeed):
-			fetchArticlesAsync(webFeed: webFeed, callback)
+			fetchArticlesAsync(webFeed: webFeed, completion)
 		case .articleIDs(let articleIDs):
-			fetchArticlesAsync(articleIDs: articleIDs, callback)
+			fetchArticlesAsync(articleIDs: articleIDs, completion)
 		case .search(let searchString):
-			fetchArticlesMatchingAsync(searchString, callback)
+			fetchArticlesMatchingAsync(searchString, completion)
 		case .searchWithArticleIDs(let searchString, let articleIDs):
-			return fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, callback)
+			return fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, completion)
 		}
 	}
 
-	public func fetchUnreadCountForToday(_ callback: @escaping (Int) -> Void) {
-		database.fetchUnreadCountForToday(for: flattenedWebFeeds().webFeedIDs(), callback: callback)
+	public func fetchUnreadCountForToday(_ completion: @escaping (Int) -> Void) {
+		database.fetchUnreadCountForToday(for: flattenedWebFeeds().webFeedIDs(), completion: completion)
 	}
 
-	public func fetchUnreadCountForStarredArticles(_ callback: @escaping (Int) -> Void) {
-		database.fetchStarredAndUnreadCount(for: flattenedWebFeeds().webFeedIDs(), callback: callback)
+	public func fetchUnreadCountForStarredArticles(_ completion: @escaping (Int) -> Void) {
+		database.fetchStarredAndUnreadCount(for: flattenedWebFeeds().webFeedIDs(), completion: completion)
 	}
 
-	public func fetchUnreadArticleIDs(_ callback: @escaping (Set<String>) -> Void) {
-		database.fetchUnreadArticleIDsAsync(webFeedIDs: flattenedWebFeeds().webFeedIDs(), callback: callback)
+	public func fetchUnreadArticleIDs(_ completion: @escaping (Set<String>) -> Void) {
+		database.fetchUnreadArticleIDsAsync(webFeedIDs: flattenedWebFeeds().webFeedIDs(), completion: completion)
 	}
 
-	public func fetchStarredArticleIDs(_ callback: @escaping (Set<String>) -> Void) {
-		database.fetchStarredArticleIDsAsync(webFeedIDs: flattenedWebFeeds().webFeedIDs(), callback: callback)
+	public func fetchStarredArticleIDs(_ completion: @escaping (Set<String>) -> Void) {
+		database.fetchStarredArticleIDsAsync(webFeedIDs: flattenedWebFeeds().webFeedIDs(), completion: completion)
 	}
 
 	public func fetchArticleIDsForStatusesWithoutArticles() -> Set<String> {
@@ -770,7 +770,7 @@ public final class Account: DisplayNameProvider, UnreadCountProvider, Container,
 	/// Fetch statuses for the specified articleIDs. The completion handler will get nil if the app is suspended.
 	/// To update the properties in the database, call the update method that takes Set<ArticleStatus> as first parameter.
 	func fetchStatuses(articleIDs: Set<String>, createIfNeeded: Bool, completion: @escaping (Set<ArticleStatus>?) -> Void) {
-		database.fetchStatuses(articleIDs: articleIDs, createIfNeeded: createIfNeeded, callback: completion)
+		database.fetchStatuses(articleIDs: articleIDs, createIfNeeded: createIfNeeded, completion: completion)
 	}
 
 	/// Empty caches that can reasonably be emptied. Call when the app goes in the background, for instance.
@@ -923,40 +923,40 @@ private extension Account {
 		return database.fetchStarredArticles(flattenedWebFeeds().webFeedIDs())
 	}
 
-	func fetchStarredArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		database.fetchedStarredArticlesAsync(flattenedWebFeeds().webFeedIDs(), callback)
+	func fetchStarredArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		database.fetchedStarredArticlesAsync(flattenedWebFeeds().webFeedIDs(), completion)
 	}
 
 	func fetchUnreadArticles() -> Set<Article> {
 		return fetchUnreadArticles(forContainer: self)
 	}
 
-	func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		fetchUnreadArticlesAsync(forContainer: self, callback)
+	func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		fetchUnreadArticlesAsync(forContainer: self, completion)
 	}
 
 	func fetchTodayArticles() -> Set<Article> {
 		return database.fetchTodayArticles(flattenedWebFeeds().webFeedIDs())
 	}
 
-	func fetchTodayArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		database.fetchTodayArticlesAsync(flattenedWebFeeds().webFeedIDs(), callback)
+	func fetchTodayArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		database.fetchTodayArticlesAsync(flattenedWebFeeds().webFeedIDs(), completion)
 	}
 
 	func fetchArticles(folder: Folder) -> Set<Article> {
 		return fetchArticles(forContainer: folder)
 	}
 
-	func fetchArticlesAsync(folder: Folder, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync(forContainer: folder, callback)
+	func fetchArticlesAsync(folder: Folder, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync(forContainer: folder, completion)
 	}
 
 	func fetchUnreadArticles(folder: Folder) -> Set<Article> {
 		return fetchUnreadArticles(forContainer: folder)
 	}
 
-	func fetchUnreadArticlesAsync(folder: Folder, _ callback: @escaping ArticleSetBlock) {
-		fetchUnreadArticlesAsync(forContainer: folder, callback)
+	func fetchUnreadArticlesAsync(folder: Folder, _ completion: @escaping ArticleSetBlock) {
+		fetchUnreadArticlesAsync(forContainer: folder, completion)
 	}
 
 	func fetchArticles(webFeed: WebFeed) -> Set<Article> {
@@ -965,10 +965,10 @@ private extension Account {
 		return articles
 	}
 
-	func fetchArticlesAsync(webFeed: WebFeed, _ callback: @escaping ArticleSetBlock) {
+	func fetchArticlesAsync(webFeed: WebFeed, _ completion: @escaping ArticleSetBlock) {
 		database.fetchArticlesAsync(webFeed.webFeedID) { [weak self] (articles) in
 			self?.validateUnreadCount(webFeed, articles)
-			callback(articles)
+			completion(articles)
 		}
 	}
 
@@ -980,20 +980,20 @@ private extension Account {
 		return database.fetchArticlesMatchingWithArticleIDs(searchString, articleIDs)
 	}
 	
-	func fetchArticlesMatchingAsync(_ searchString: String, _ callback: @escaping ArticleSetBlock) {
-		database.fetchArticlesMatchingAsync(searchString, flattenedWebFeeds().webFeedIDs(), callback)
+	func fetchArticlesMatchingAsync(_ searchString: String, _ completion: @escaping ArticleSetBlock) {
+		database.fetchArticlesMatchingAsync(searchString, flattenedWebFeeds().webFeedIDs(), completion)
 	}
 
-	func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		database.fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, callback)
+	func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		database.fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, completion)
 	}
 
 	func fetchArticles(articleIDs: Set<String>) -> Set<Article> {
 		return database.fetchArticles(articleIDs: articleIDs)
 	}
 
-	func fetchArticlesAsync(articleIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		return database.fetchArticlesAsync(articleIDs: articleIDs, callback)
+	func fetchArticlesAsync(articleIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		return database.fetchArticlesAsync(articleIDs: articleIDs, completion)
 	}
 
 	func fetchUnreadArticles(webFeed: WebFeed) -> Set<Article> {
@@ -1002,7 +1002,7 @@ private extension Account {
 		return articles
 	}
 
-	func fetchUnreadArticlesAsync(for webFeed: WebFeed, callback: @escaping (Set<Article>) -> Void) {
+	func fetchUnreadArticlesAsync(for webFeed: WebFeed, completion: @escaping (Set<Article>) -> Void) {
 		//		database.fetchUnreadArticlesAsync(for: Set([feed.feedID])) { [weak self] (articles) in
 		//			self?.validateUnreadCount(feed, articles)
 		//			callback(articles)
@@ -1017,11 +1017,11 @@ private extension Account {
 		return articles
 	}
 
-	func fetchArticlesAsync(forContainer container: Container, _ callback: @escaping ArticleSetBlock) {
+	func fetchArticlesAsync(forContainer container: Container, _ completion: @escaping ArticleSetBlock) {
 		let webFeeds = container.flattenedWebFeeds()
 		database.fetchArticlesAsync(webFeeds.webFeedIDs()) { [weak self] (articles) in
 			self?.validateUnreadCountsAfterFetchingUnreadArticles(webFeeds, articles)
-			callback(articles)
+			completion(articles)
 		}
 	}
 
@@ -1032,11 +1032,11 @@ private extension Account {
 		return articles
 	}
 
-	func fetchUnreadArticlesAsync(forContainer container: Container, _ callback: @escaping ArticleSetBlock) {
+	func fetchUnreadArticlesAsync(forContainer container: Container, _ completion: @escaping ArticleSetBlock) {
 		let webFeeds = container.flattenedWebFeeds()
 		database.fetchUnreadArticlesAsync(webFeeds.webFeedIDs()) { [weak self] (articles) in
 			self?.validateUnreadCountsAfterFetchingUnreadArticles(webFeeds, articles)
-			callback(articles)
+			completion(articles)
 		}
 	}
 
diff --git a/Frameworks/Account/AccountManager.swift b/Frameworks/Account/AccountManager.swift
index 49133a52b..f3badd13d 100644
--- a/Frameworks/Account/AccountManager.swift
+++ b/Frameworks/Account/AccountManager.swift
@@ -265,7 +265,7 @@ public final class AccountManager: UnreadCountProvider {
 		return articles
 	}
 
-	public func fetchArticlesAsync(_ fetchType: FetchType, _ callback: @escaping ArticleSetBlock) {
+	public func fetchArticlesAsync(_ fetchType: FetchType, _ completion: @escaping ArticleSetBlock) {
 		precondition(Thread.isMainThread)
 		
 		var allFetchedArticles = Set<Article>()
@@ -277,7 +277,7 @@ public final class AccountManager: UnreadCountProvider {
 				allFetchedArticles.formUnion(articles)
 				accountsReporting += 1
 				if accountsReporting == numberOfAccounts {
-					callback(allFetchedArticles)
+					completion(allFetchedArticles)
 				}
 			}
 		}
diff --git a/Frameworks/Account/ArticleFetcher.swift b/Frameworks/Account/ArticleFetcher.swift
index bf4b08dac..a92d1e928 100644
--- a/Frameworks/Account/ArticleFetcher.swift
+++ b/Frameworks/Account/ArticleFetcher.swift
@@ -12,9 +12,9 @@ import Articles
 public protocol ArticleFetcher {
 
 	func fetchArticles() -> Set<Article>
-	func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock)
+	func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock)
 	func fetchUnreadArticles() -> Set<Article>
-	func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock)
+	func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock)
 }
 
 extension WebFeed: ArticleFetcher {
@@ -23,26 +23,26 @@ extension WebFeed: ArticleFetcher {
 		return account?.fetchArticles(.webFeed(self)) ?? Set<Article>()
 	}
 
-	public func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
+	public func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
 		guard let account = account else {
 			assertionFailure("Expected feed.account, but got nil.")
-			callback(Set<Article>())
+			completion(Set<Article>())
 			return
 		}
-		account.fetchArticlesAsync(.webFeed(self), callback)
+		account.fetchArticlesAsync(.webFeed(self), completion)
 	}
 
 	public func fetchUnreadArticles() -> Set<Article> {
 		return fetchArticles().unreadArticles()
 	}
 
-	public func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
+	public func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
 		guard let account = account else {
 			assertionFailure("Expected feed.account, but got nil.")
-			callback(Set<Article>())
+			completion(Set<Article>())
 			return
 		}
-		account.fetchArticlesAsync(.webFeed(self)) { callback($0.unreadArticles()) }
+		account.fetchArticlesAsync(.webFeed(self)) { completion($0.unreadArticles()) }
 	}
 }
 
@@ -56,13 +56,13 @@ extension Folder: ArticleFetcher {
 		return account.fetchArticles(.folder(self, false))
 	}
 
-	public func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
+	public func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
 		guard let account = account else {
 			assertionFailure("Expected folder.account, but got nil.")
-			callback(Set<Article>())
+			completion(Set<Article>())
 			return
 		}
-		account.fetchArticlesAsync(.folder(self, false), callback)
+		account.fetchArticlesAsync(.folder(self, false), completion)
 	}
 
 	public func fetchUnreadArticles() -> Set<Article> {
@@ -73,12 +73,12 @@ extension Folder: ArticleFetcher {
 		return account.fetchArticles(.folder(self, true))
 	}
 
-	public func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
+	public func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
 		guard let account = account else {
 			assertionFailure("Expected folder.account, but got nil.")
-			callback(Set<Article>())
+			completion(Set<Article>())
 			return
 		}
-		account.fetchArticlesAsync(.folder(self, true), callback)
+		account.fetchArticlesAsync(.folder(self, true), completion)
 	}
 }
diff --git a/Frameworks/Account/SingleArticleFetcher.swift b/Frameworks/Account/SingleArticleFetcher.swift
index 960a136e4..d600c52b5 100644
--- a/Frameworks/Account/SingleArticleFetcher.swift
+++ b/Frameworks/Account/SingleArticleFetcher.swift
@@ -23,16 +23,16 @@ public struct SingleArticleFetcher: ArticleFetcher {
 		return account.fetchArticles(.articleIDs(Set([articleID])))
 	}
 	
-	public func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		return account.fetchArticlesAsync(.articleIDs(Set([articleID])), callback)
+	public func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		return account.fetchArticlesAsync(.articleIDs(Set([articleID])), completion)
 	}
 	
 	public func fetchUnreadArticles() -> Set<Article> {
 		return account.fetchArticles(.articleIDs(Set([articleID])))
 	}
 	
-	public func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		return account.fetchArticlesAsync(.articleIDs(Set([articleID])), callback)
+	public func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		return account.fetchArticlesAsync(.articleIDs(Set([articleID])), completion)
 	}
 	
 }
diff --git a/Frameworks/ArticlesDatabase/ArticlesDatabase.swift b/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
index 5d3bee42a..2ba95bdcf 100644
--- a/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
+++ b/Frameworks/ArticlesDatabase/ArticlesDatabase.swift
@@ -87,58 +87,58 @@ public final class ArticlesDatabase {
 
 	// MARK: - Fetching Articles Async
 
-	public func fetchArticlesAsync(_ webFeedID: String, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchArticlesAsync(webFeedID, callback)
+	public func fetchArticlesAsync(_ webFeedID: String, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchArticlesAsync(webFeedID, completion)
 	}
 
-	public func fetchArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchArticlesAsync(webFeedIDs, callback)
+	public func fetchArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchArticlesAsync(webFeedIDs, completion)
 	}
 
-	public func fetchArticlesAsync(articleIDs: Set<String>, _ callback: @escaping  ArticleSetBlock) {
-		articlesTable.fetchArticlesAsync(articleIDs: articleIDs, callback)
+	public func fetchArticlesAsync(articleIDs: Set<String>, _ completion: @escaping  ArticleSetBlock) {
+		articlesTable.fetchArticlesAsync(articleIDs: articleIDs, completion)
 	}
 
-	public func fetchUnreadArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchUnreadArticlesAsync(webFeedIDs, callback)
+	public func fetchUnreadArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchUnreadArticlesAsync(webFeedIDs, completion)
 	}
 
-	public func fetchTodayArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchArticlesSinceAsync(webFeedIDs, todayCutoffDate(), callback)
+	public func fetchTodayArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchArticlesSinceAsync(webFeedIDs, todayCutoffDate(), completion)
 	}
 
-	public func fetchedStarredArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchStarredArticlesAsync(webFeedIDs, callback)
+	public func fetchedStarredArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchStarredArticlesAsync(webFeedIDs, completion)
 	}
 
-	public func fetchArticlesMatchingAsync(_ searchString: String, _ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchArticlesMatchingAsync(searchString, webFeedIDs, callback)
+	public func fetchArticlesMatchingAsync(_ searchString: String, _ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchArticlesMatchingAsync(searchString, webFeedIDs, completion)
 	}
 
-	public func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		articlesTable.fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, callback)
+	public func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		articlesTable.fetchArticlesMatchingWithArticleIDsAsync(searchString, articleIDs, completion)
 	}
 
 	// MARK: - Unread Counts
 	
-	public func fetchUnreadCounts(for webFeedIDs: Set<String>, _ callback: @escaping UnreadCountCompletionBlock) {
-		articlesTable.fetchUnreadCounts(webFeedIDs, callback)
+	public func fetchUnreadCounts(for webFeedIDs: Set<String>, _ completion: @escaping UnreadCountCompletionBlock) {
+		articlesTable.fetchUnreadCounts(webFeedIDs, completion)
 	}
 
-	public func fetchUnreadCountForToday(for webFeedIDs: Set<String>, callback: @escaping (Int) -> Void) {
-		fetchUnreadCount(for: webFeedIDs, since: todayCutoffDate(), callback: callback)
+	public func fetchUnreadCountForToday(for webFeedIDs: Set<String>, completion: @escaping (Int) -> Void) {
+		fetchUnreadCount(for: webFeedIDs, since: todayCutoffDate(), completion: completion)
 	}
 
-	public func fetchUnreadCount(for webFeedIDs: Set<String>, since: Date, callback: @escaping (Int) -> Void) {
-		articlesTable.fetchUnreadCount(webFeedIDs, since, callback)
+	public func fetchUnreadCount(for webFeedIDs: Set<String>, since: Date, completion: @escaping (Int) -> Void) {
+		articlesTable.fetchUnreadCount(webFeedIDs, since, completion)
 	}
 
-	public func fetchStarredAndUnreadCount(for webFeedIDs: Set<String>, callback: @escaping (Int) -> Void) {
-		articlesTable.fetchStarredAndUnreadCount(webFeedIDs, callback)
+	public func fetchStarredAndUnreadCount(for webFeedIDs: Set<String>, completion: @escaping (Int) -> Void) {
+		articlesTable.fetchStarredAndUnreadCount(webFeedIDs, completion)
 	}
 
-	public func fetchAllNonZeroUnreadCounts(_ callback: @escaping UnreadCountCompletionBlock) {
-		articlesTable.fetchAllUnreadCounts(callback)
+	public func fetchAllNonZeroUnreadCounts(_ completion: @escaping UnreadCountCompletionBlock) {
+		articlesTable.fetchAllUnreadCounts(completion)
 	}
 
 	// MARK: - Saving and Updating Articles
@@ -155,13 +155,13 @@ public final class ArticlesDatabase {
 	// MARK: - Status
 
 	/// Fetch the articleIDs of unread articles in feeds specified by webFeedIDs.
-	public func fetchUnreadArticleIDsAsync(webFeedIDs: Set<String>, callback: @escaping (Set<String>) -> Void) {
-		articlesTable.fetchUnreadArticleIDsAsync(webFeedIDs, callback)
+	public func fetchUnreadArticleIDsAsync(webFeedIDs: Set<String>, completion: @escaping (Set<String>) -> Void) {
+		articlesTable.fetchUnreadArticleIDsAsync(webFeedIDs, completion)
 	}
 	
 	/// Fetch the articleIDs of starred articles in feeds specified by webFeedIDs.
-	public func fetchStarredArticleIDsAsync(webFeedIDs: Set<String>, callback: @escaping (Set<String>) -> Void) {
-		articlesTable.fetchStarredArticleIDsAsync(webFeedIDs, callback)
+	public func fetchStarredArticleIDsAsync(webFeedIDs: Set<String>, completion: @escaping (Set<String>) -> Void) {
+		articlesTable.fetchStarredArticleIDsAsync(webFeedIDs, completion)
 	}
 
 	public func fetchArticleIDsForStatusesWithoutArticles() -> Set<String> {
@@ -172,8 +172,8 @@ public final class ArticlesDatabase {
 		return articlesTable.mark(articles, statusKey, flag)
 	}
 
-	public func fetchStatuses(articleIDs: Set<String>, createIfNeeded: Bool, callback: @escaping (Set<ArticleStatus>?) -> Void) {
-		articlesTable.fetchStatuses(articleIDs, createIfNeeded, callback)
+	public func fetchStatuses(articleIDs: Set<String>, createIfNeeded: Bool, completion: @escaping (Set<ArticleStatus>?) -> Void) {
+		articlesTable.fetchStatuses(articleIDs, createIfNeeded, completion)
 	}
 
 	// MARK: - Suspend and Resume (for iOS)
diff --git a/Frameworks/ArticlesDatabase/ArticlesTable.swift b/Frameworks/ArticlesDatabase/ArticlesTable.swift
index c94990191..5e661f240 100644
--- a/Frameworks/ArticlesDatabase/ArticlesTable.swift
+++ b/Frameworks/ArticlesDatabase/ArticlesTable.swift
@@ -47,8 +47,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchArticlesForFeedID(webFeedID, withLimits: true, $0) }
 	}
 
-	func fetchArticlesAsync(_ webFeedID: String, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchArticlesForFeedID(webFeedID, withLimits: true, $0) }, callback)
+	func fetchArticlesAsync(_ webFeedID: String, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchArticlesForFeedID(webFeedID, withLimits: true, $0) }, completion)
 	}
 
 	private func fetchArticlesForFeedID(_ webFeedID: String, withLimits: Bool, _ database: FMDatabase) -> Set<Article> {
@@ -59,8 +59,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchArticles(webFeedIDs, $0) }
 	}
 
-	func fetchArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchArticles(webFeedIDs, $0) }, callback)
+	func fetchArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchArticles(webFeedIDs, $0) }, completion)
 	}
 
 	private func fetchArticles(_ webFeedIDs: Set<String>, _ database: FMDatabase) -> Set<Article> {
@@ -80,8 +80,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchArticles(articleIDs: articleIDs, $0) }
 	}
 
-	func fetchArticlesAsync(articleIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		return fetchArticlesAsync({ self.fetchArticles(articleIDs: articleIDs, $0) }, callback)
+	func fetchArticlesAsync(articleIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		return fetchArticlesAsync({ self.fetchArticles(articleIDs: articleIDs, $0) }, completion)
 	}
 
 	private func fetchArticles(articleIDs: Set<String>, _ database: FMDatabase) -> Set<Article> {
@@ -100,8 +100,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchUnreadArticles(webFeedIDs, $0) }
 	}
 
-	func fetchUnreadArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchUnreadArticles(webFeedIDs, $0) }, callback)
+	func fetchUnreadArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchUnreadArticles(webFeedIDs, $0) }, completion)
 	}
 
 	private func fetchUnreadArticles(_ webFeedIDs: Set<String>, _ database: FMDatabase) -> Set<Article> {
@@ -121,8 +121,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchArticlesSince(webFeedIDs, cutoffDate, $0) }
 	}
 
-	func fetchArticlesSinceAsync(_ webFeedIDs: Set<String>, _ cutoffDate: Date, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchArticlesSince(webFeedIDs, cutoffDate, $0) }, callback)
+	func fetchArticlesSinceAsync(_ webFeedIDs: Set<String>, _ cutoffDate: Date, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchArticlesSince(webFeedIDs, cutoffDate, $0) }, completion)
 	}
 
 	private func fetchArticlesSince(_ webFeedIDs: Set<String>, _ cutoffDate: Date, _ database: FMDatabase) -> Set<Article> {
@@ -144,8 +144,8 @@ final class ArticlesTable: DatabaseTable {
 		return fetchArticles{ self.fetchStarredArticles(webFeedIDs, $0) }
 	}
 
-	func fetchStarredArticlesAsync(_ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchStarredArticles(webFeedIDs, $0) }, callback)
+	func fetchStarredArticlesAsync(_ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchStarredArticles(webFeedIDs, $0) }, completion)
 	}
 
 	private func fetchStarredArticles(_ webFeedIDs: Set<String>, _ database: FMDatabase) -> Set<Article> {
@@ -184,12 +184,12 @@ final class ArticlesTable: DatabaseTable {
 		return articles
 	}
 
-	func fetchArticlesMatchingAsync(_ searchString: String, _ webFeedIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchArticlesMatching(searchString, webFeedIDs, $0) }, callback)
+	func fetchArticlesMatchingAsync(_ searchString: String, _ webFeedIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchArticlesMatching(searchString, webFeedIDs, $0) }, completion)
 	}
 
-	func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync({ self.fetchArticlesMatchingWithArticleIDs(searchString, articleIDs, $0) }, callback)
+	func fetchArticlesMatchingWithArticleIDsAsync(_ searchString: String, _ articleIDs: Set<String>, _ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync({ self.fetchArticlesMatchingWithArticleIDs(searchString, articleIDs, $0) }, completion)
 	}
 
 	private func fetchArticlesMatching(_ searchString: String, _ webFeedIDs: Set<String>, _ database: FMDatabase) -> Set<Article> {
@@ -311,9 +311,9 @@ final class ArticlesTable: DatabaseTable {
 		}
 	}
 
-	func fetchStatuses(_ articleIDs: Set<String>, _ createIfNeeded: Bool, _ callback: @escaping (Set<ArticleStatus>?) -> Void) {
+	func fetchStatuses(_ articleIDs: Set<String>, _ createIfNeeded: Bool, _ completion: @escaping (Set<ArticleStatus>?) -> Void) {
 		guard !queue.isSuspended else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
@@ -327,7 +327,7 @@ final class ArticlesTable: DatabaseTable {
 			}
 			let statuses = Set(statusesDictionary.values)
 			DispatchQueue.main.async {
-				callback(statuses)
+				completion(statuses)
 			}
 		}
 	}
@@ -357,11 +357,11 @@ final class ArticlesTable: DatabaseTable {
 		}
 	}
 
-	func fetchUnreadCount(_ webFeedIDs: Set<String>, _ since: Date, _ callback: @escaping (Int) -> Void) {
+	func fetchUnreadCount(_ webFeedIDs: Set<String>, _ since: Date, _ completion: @escaping (Int) -> Void) {
 		// Get unread count for today, for instance.
 
 		if webFeedIDs.isEmpty || queue.isSuspended {
-			callback(0)
+			completion(0)
 			return
 		}
 		
@@ -377,7 +377,7 @@ final class ArticlesTable: DatabaseTable {
 			let unreadCount = self.numberWithSQLAndParameters(sql, parameters, in: database)
 
 			DispatchQueue.main.async {
-				callback(unreadCount)
+				completion(unreadCount)
 			}
 		}
 	}
@@ -416,9 +416,9 @@ final class ArticlesTable: DatabaseTable {
 		}
 	}
 
-	func fetchStarredAndUnreadCount(_ webFeedIDs: Set<String>, _ callback: @escaping (Int) -> Void) {
+	func fetchStarredAndUnreadCount(_ webFeedIDs: Set<String>, _ completion: @escaping (Int) -> Void) {
 		if webFeedIDs.isEmpty || queue.isSuspended {
-			callback(0)
+			completion(0)
 			return
 		}
 
@@ -430,19 +430,19 @@ final class ArticlesTable: DatabaseTable {
 			let unreadCount = self.numberWithSQLAndParameters(sql, parameters, in: database)
 
 			DispatchQueue.main.async {
-				callback(unreadCount)
+				completion(unreadCount)
 			}
 		}
 	}
 
 	// MARK: - Statuses
 	
-	func fetchUnreadArticleIDsAsync(_ webFeedIDs: Set<String>, _ callback: @escaping (Set<String>) -> Void) {
-		fetchArticleIDsAsync(.read, false, webFeedIDs, callback)
+	func fetchUnreadArticleIDsAsync(_ webFeedIDs: Set<String>, _ completion: @escaping (Set<String>) -> Void) {
+		fetchArticleIDsAsync(.read, false, webFeedIDs, completion)
 	}
 
-	func fetchStarredArticleIDsAsync(_ webFeedIDs: Set<String>, _ callback: @escaping (Set<String>) -> Void) {
-		fetchArticleIDsAsync(.starred, true, webFeedIDs, callback)
+	func fetchStarredArticleIDsAsync(_ webFeedIDs: Set<String>, _ completion: @escaping (Set<String>) -> Void) {
+		fetchArticleIDsAsync(.starred, true, webFeedIDs, completion)
 	}
 
 	func fetchStarredArticleIDs() -> Set<String> {
@@ -541,15 +541,15 @@ private extension ArticlesTable {
 		return articles
 	}
 
-	private func fetchArticlesAsync(_ fetchMethod: @escaping ArticlesFetchMethod, _ callback: @escaping ArticleSetBlock) {
+	private func fetchArticlesAsync(_ fetchMethod: @escaping ArticlesFetchMethod, _ completion: @escaping ArticleSetBlock) {
 		guard !queue.isSuspended else {
-			callback(Set<Article>())
+			completion(Set<Article>())
 			return
 		}
 		queue.runInDatabase { (database) in
 			let articles = fetchMethod(database)
 			DispatchQueue.main.async {
-				callback(articles)
+				completion(articles)
 			}
 		}
 	}
@@ -702,9 +702,9 @@ private extension ArticlesTable {
 		return articlesWithResultSet(resultSet, database)
 	}
 
-	func fetchArticleIDsAsync(_ statusKey: ArticleStatus.Key, _ value: Bool, _ webFeedIDs: Set<String>, _ callback: @escaping (Set<String>) -> Void) {
+	func fetchArticleIDsAsync(_ statusKey: ArticleStatus.Key, _ value: Bool, _ webFeedIDs: Set<String>, _ completion: @escaping (Set<String>) -> Void) {
 		guard !queue.isSuspended && !webFeedIDs.isEmpty else {
-			callback(Set<String>())
+			completion(Set<String>())
 			return
 		}
 		queue.runInDatabase { database in
@@ -720,14 +720,14 @@ private extension ArticlesTable {
 
 			guard let resultSet = database.executeQuery(sql, withArgumentsIn: parameters) else {
 				DispatchQueue.main.async {
-					callback(Set<String>())
+					completion(Set<String>())
 				}
 				return
 			}
 
 			let articleIDs = resultSet.mapToSet{ $0.string(forColumnIndex: 0) }
 			DispatchQueue.main.async {
-				callback(articleIDs)
+				completion(articleIDs)
 			}
 		}
 	}
diff --git a/Mac/MainWindow/Detail/DetailViewController.swift b/Mac/MainWindow/Detail/DetailViewController.swift
index 0e3def9e9..f5039d07e 100644
--- a/Mac/MainWindow/Detail/DetailViewController.swift
+++ b/Mac/MainWindow/Detail/DetailViewController.swift
@@ -58,8 +58,8 @@ final class DetailViewController: NSViewController, WKUIDelegate {
 		currentWebViewController = webViewController(for: mode)
 	}
 
-	func canScrollDown(_ callback: @escaping (Bool) -> Void) {
-		currentWebViewController.canScrollDown(callback)
+	func canScrollDown(_ completion: @escaping (Bool) -> Void) {
+		currentWebViewController.canScrollDown(completion)
 	}
 
 	override func scrollPageDown(_ sender: Any?) {
diff --git a/Mac/MainWindow/Detail/DetailWebViewController.swift b/Mac/MainWindow/Detail/DetailWebViewController.swift
index 1ef693fbe..1a334a958 100644
--- a/Mac/MainWindow/Detail/DetailWebViewController.swift
+++ b/Mac/MainWindow/Detail/DetailWebViewController.swift
@@ -127,9 +127,9 @@ final class DetailWebViewController: NSViewController, WKUIDelegate {
 	
 	// MARK: Scrolling
 
-	func canScrollDown(_ callback: @escaping (Bool) -> Void) {
+	func canScrollDown(_ completion: @escaping (Bool) -> Void) {
 		fetchScrollInfo { (scrollInfo) in
-			callback(scrollInfo?.canScrollDown ?? false)
+			completion(scrollInfo?.canScrollDown ?? false)
 		}
 	}
 
@@ -227,7 +227,7 @@ private extension DetailWebViewController {
 		webView.evaluateJavaScript(render)
 	}
 
-	func fetchScrollInfo(_ callback: @escaping (ScrollInfo?) -> Void) {
+	func fetchScrollInfo(_ completion: @escaping (ScrollInfo?) -> Void) {
 		var javascriptString = "var x = {contentHeight: document.body.scrollHeight, offsetY: document.body.scrollTop}; x"
 		if #available(macOS 10.15, *) {
 			javascriptString = "var x = {contentHeight: document.body.scrollHeight, offsetY: window.pageYOffset}; x"
@@ -235,16 +235,16 @@ private extension DetailWebViewController {
 
 		webView.evaluateJavaScript(javascriptString) { (info, error) in
 			guard let info = info as? [String: Any] else {
-				callback(nil)
+				completion(nil)
 				return
 			}
 			guard let contentHeight = info["contentHeight"] as? CGFloat, let offsetY = info["offsetY"] as? CGFloat else {
-				callback(nil)
+				completion(nil)
 				return
 			}
 
 			let scrollInfo = ScrollInfo(contentHeight: contentHeight, viewHeight: self.webView.frame.height, offsetY: offsetY)
-			callback(scrollInfo)
+			completion(scrollInfo)
 		}
 	}
 
diff --git a/Mac/MainWindow/Sidebar/SidebarViewController.swift b/Mac/MainWindow/Sidebar/SidebarViewController.swift
index 1744a57c6..f1afc1a0e 100644
--- a/Mac/MainWindow/Sidebar/SidebarViewController.swift
+++ b/Mac/MainWindow/Sidebar/SidebarViewController.swift
@@ -595,19 +595,19 @@ private extension SidebarViewController {
 		return rowView.view(atColumn: 0) as? SidebarCell
 	}
 
-	func applyToAvailableCells(_ callback: (SidebarCell, Node) -> Void) {
+	func applyToAvailableCells(_ completion: (SidebarCell, Node) -> Void) {
 		outlineView.enumerateAvailableRowViews { (rowView: NSTableRowView, row: Int) -> Void in
 			guard let cell = cellForRowView(rowView), let node = nodeForRow(row) else {
 				return
 			}
-			callback(cell, node)
+			completion(cell, node)
 		}
 	}
 
-	func applyToCellsForRepresentedObject(_ representedObject: AnyObject, _ callback: (SidebarCell, Node) -> Void) {
+	func applyToCellsForRepresentedObject(_ representedObject: AnyObject, _ completion: (SidebarCell, Node) -> Void) {
 		applyToAvailableCells { (cell, node) in
 			if node.representsSidebarObject(representedObject) {
-				callback(cell, node)
+				completion(cell, node)
 			}
 		}
 	}
diff --git a/Mac/MainWindow/Timeline/TimelineViewController.swift b/Mac/MainWindow/Timeline/TimelineViewController.swift
index 65b7366b1..1ffdfa86a 100644
--- a/Mac/MainWindow/Timeline/TimelineViewController.swift
+++ b/Mac/MainWindow/Timeline/TimelineViewController.swift
@@ -1027,7 +1027,7 @@ private extension TimelineViewController {
 		return fetchedArticles
 	}
 
-	func fetchUnsortedArticlesAsync(for representedObjects: [Any], callback: @escaping ArticleSetBlock) {
+	func fetchUnsortedArticlesAsync(for representedObjects: [Any], completion: @escaping ArticleSetBlock) {
 		// The callback will *not* be called if the fetch is no longer relevant — that is,
 		// if it’s been superseded by a newer fetch, or the timeline was emptied, etc., it won’t get called.
 		precondition(Thread.isMainThread)
@@ -1038,7 +1038,7 @@ private extension TimelineViewController {
 			guard !operation.isCanceled, let strongSelf = self, operation.id == strongSelf.fetchSerialNumber else {
 				return
 			}
-			callback(articles)
+			completion(articles)
 		}
 		fetchRequestQueue.add(fetchOperation)
 	}
diff --git a/Shared/Favicons/FaviconURLFinder.swift b/Shared/Favicons/FaviconURLFinder.swift
index 766ad0451..654dd1f3b 100644
--- a/Shared/Favicons/FaviconURLFinder.swift
+++ b/Shared/Favicons/FaviconURLFinder.swift
@@ -13,15 +13,15 @@ import RSParser
 
 struct FaviconURLFinder {
 
-	static func findFaviconURLs(_ homePageURL: String, _ callback: @escaping ([String]?) -> Void) {
+	static func findFaviconURLs(_ homePageURL: String, _ completion: @escaping ([String]?) -> Void) {
 
 		guard let _ = URL(string: homePageURL) else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
 		HTMLMetadataDownloader.downloadMetadata(for: homePageURL) { (htmlMetadata) in
-			callback(htmlMetadata?.faviconLinks)
+			completion(htmlMetadata?.faviconLinks)
 		}
 	}
 }
diff --git a/Shared/Favicons/SingleFaviconDownloader.swift b/Shared/Favicons/SingleFaviconDownloader.swift
index a7d4fd288..d4b91283f 100644
--- a/Shared/Favicons/SingleFaviconDownloader.swift
+++ b/Shared/Favicons/SingleFaviconDownloader.swift
@@ -93,22 +93,22 @@ private extension SingleFaviconDownloader {
 		}
 	}
 
-	func readFromDisk(_ callback: @escaping (RSImage?) -> Void) {
+	func readFromDisk(_ completion: @escaping (RSImage?) -> Void) {
 
 		guard diskStatus != .notOnDisk else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
 		queue.async {
 
 			if let data = self.diskCache[self.diskKey], !data.isEmpty {
-				RSImage.rs_image(with: data, imageResultBlock: callback)
+				RSImage.rs_image(with: data, imageResultBlock: completion)
 				return
 			}
 
 			DispatchQueue.main.async {
-				callback(nil)
+				completion(nil)
 			}
 		}
 	}
@@ -127,10 +127,10 @@ private extension SingleFaviconDownloader {
 		}
 	}
 
-	func downloadFavicon(_ callback: @escaping (RSImage?) -> Void) {
+	func downloadFavicon(_ completion: @escaping (RSImage?) -> Void) {
 
 		guard let url = URL(string: faviconURL) else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
@@ -138,7 +138,7 @@ private extension SingleFaviconDownloader {
 
 			if let data = data, !data.isEmpty, let response = response, response.statusIsOK, error == nil {
 				self.saveToDisk(data)
-				RSImage.rs_image(with: data, imageResultBlock: callback)
+				RSImage.rs_image(with: data, imageResultBlock: completion)
 				return
 			}
 
@@ -146,7 +146,7 @@ private extension SingleFaviconDownloader {
 				appDelegate.logMessage("Error downloading favicon at \(url): \(error)", type: .warning)
 			}
 
-			callback(nil)
+			completion(nil)
 		}
 	}
 
diff --git a/Shared/HTMLMetadata/HTMLMetadataDownloader.swift b/Shared/HTMLMetadata/HTMLMetadataDownloader.swift
index 1e7b325d1..327257782 100644
--- a/Shared/HTMLMetadata/HTMLMetadataDownloader.swift
+++ b/Shared/HTMLMetadata/HTMLMetadataDownloader.swift
@@ -14,9 +14,9 @@ struct HTMLMetadataDownloader {
 
 	static let serialDispatchQueue = DispatchQueue(label: "HTMLMetadataDownloader")
 
-	static func downloadMetadata(for url: String, _ callback: @escaping (RSHTMLMetadata?) -> Void) {
+	static func downloadMetadata(for url: String, _ completion: @escaping (RSHTMLMetadata?) -> Void) {
 		guard let actualURL = URL(string: url) else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
@@ -24,7 +24,7 @@ struct HTMLMetadataDownloader {
 			if let data = data, !data.isEmpty, let response = response, response.statusIsOK, error == nil {
 				let urlToUse = response.url ?? actualURL
 				let parserData = ParserData(url: urlToUse.absoluteString, data: data)
-				parseMetadata(with: parserData, callback)
+				parseMetadata(with: parserData, completion)
 				return
 			}
 
@@ -32,15 +32,15 @@ struct HTMLMetadataDownloader {
 				appDelegate.logMessage("Error downloading metadata at \(url): \(error)", type: .warning)
 			}
 
-			callback(nil)
+			completion(nil)
 		}
 	}
 
-	private static func parseMetadata(with parserData: ParserData, _ callback: @escaping (RSHTMLMetadata?) -> Void) {
+	private static func parseMetadata(with parserData: ParserData, _ completion: @escaping (RSHTMLMetadata?) -> Void) {
 		serialDispatchQueue.async {
 			let htmlMetadata = RSHTMLMetadataParser.htmlMetadata(with: parserData)
 			DispatchQueue.main.async {
-				callback(htmlMetadata)
+				completion(htmlMetadata)
 			}
 		}
 	}
diff --git a/Shared/Images/ImageDownloader.swift b/Shared/Images/ImageDownloader.swift
index 299aba887..289ef74fe 100644
--- a/Shared/Images/ImageDownloader.swift
+++ b/Shared/Images/ImageDownloader.swift
@@ -76,27 +76,27 @@ private extension ImageDownloader {
 		}
 	}
 
-	func readFromDisk(_ url: String, _ callback: @escaping (Data?) -> Void) {
+	func readFromDisk(_ url: String, _ completion: @escaping (Data?) -> Void) {
 
 		queue.async {
 
 			if let data = self.diskCache[self.diskKey(url)], !data.isEmpty {
 				DispatchQueue.main.async {
-					callback(data)
+					completion(data)
 				}
 				return
 			}
 
 			DispatchQueue.main.async {
-				callback(nil)
+				completion(nil)
 			}
 		}
 	}
 
-	func downloadImage(_ url: String, _ callback: @escaping (Data?) -> Void) {
+	func downloadImage(_ url: String, _ completion: @escaping (Data?) -> Void) {
 
 		guard let imageURL = URL(string: url) else {
-			callback(nil)
+			completion(nil)
 			return
 		}
 
@@ -104,7 +104,7 @@ private extension ImageDownloader {
 
 			if let data = data, !data.isEmpty, let response = response, response.statusIsOK, error == nil {
 				self.saveToDisk(url, data)
-				callback(data)
+				completion(data)
 				return
 			}
 
@@ -115,7 +115,7 @@ private extension ImageDownloader {
 				appDelegate.logMessage("Error downloading image at \(url): \(error)", type: .warning)
 			}
 
-			callback(nil)
+			completion(nil)
 		}
 	}
 
diff --git a/Shared/SmartFeeds/SearchFeedDelegate.swift b/Shared/SmartFeeds/SearchFeedDelegate.swift
index aacbc704c..dbeac37bd 100644
--- a/Shared/SmartFeeds/SearchFeedDelegate.swift
+++ b/Shared/SmartFeeds/SearchFeedDelegate.swift
@@ -31,7 +31,7 @@ struct SearchFeedDelegate: SmartFeedDelegate {
 		self.fetchType = .search(searchString)
 	}
 
-	func fetchUnreadCount(for: Account, callback: @escaping (Int) -> Void) {
+	func fetchUnreadCount(for: Account, completion: @escaping (Int) -> Void) {
 		// TODO: after 5.0
 	}
 }
diff --git a/Shared/SmartFeeds/SearchTimelineFeedDelegate.swift b/Shared/SmartFeeds/SearchTimelineFeedDelegate.swift
index 3d2af5fb5..f67a8b397 100644
--- a/Shared/SmartFeeds/SearchTimelineFeedDelegate.swift
+++ b/Shared/SmartFeeds/SearchTimelineFeedDelegate.swift
@@ -31,7 +31,7 @@ struct SearchTimelineFeedDelegate: SmartFeedDelegate {
 		self.fetchType = .searchWithArticleIDs(searchString, articleIDs)
 	}
 
-	func fetchUnreadCount(for: Account, callback: @escaping (Int) -> Void) {
+	func fetchUnreadCount(for: Account, completion: @escaping (Int) -> Void) {
 		// TODO: after 5.0
 	}
 }
diff --git a/Shared/SmartFeeds/SmartFeed.swift b/Shared/SmartFeeds/SmartFeed.swift
index b6302ad44..75090bbff 100644
--- a/Shared/SmartFeeds/SmartFeed.swift
+++ b/Shared/SmartFeeds/SmartFeed.swift
@@ -84,16 +84,16 @@ extension SmartFeed: ArticleFetcher {
 		return delegate.fetchArticles()
 	}
 
-	func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		delegate.fetchArticlesAsync(callback)
+	func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		delegate.fetchArticlesAsync(completion)
 	}
 
 	func fetchUnreadArticles() -> Set<Article> {
 		return delegate.fetchUnreadArticles()
 	}
 
-	func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		delegate.fetchUnreadArticlesAsync(callback)
+	func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		delegate.fetchUnreadArticlesAsync(completion)
 	}
 }
 
diff --git a/Shared/SmartFeeds/SmartFeedDelegate.swift b/Shared/SmartFeeds/SmartFeedDelegate.swift
index 2f831a8e8..9bd7d5341 100644
--- a/Shared/SmartFeeds/SmartFeedDelegate.swift
+++ b/Shared/SmartFeeds/SmartFeedDelegate.swift
@@ -13,7 +13,7 @@ import RSCore
 
 protocol SmartFeedDelegate: FeedIdentifiable, DisplayNameProvider, ArticleFetcher, SmallIconProvider {
 	var fetchType: FetchType { get }
-	func fetchUnreadCount(for: Account, callback: @escaping (Int) -> Void)
+	func fetchUnreadCount(for: Account, completion: @escaping (Int) -> Void)
 }
 
 extension SmartFeedDelegate {
@@ -22,15 +22,15 @@ extension SmartFeedDelegate {
 		return AccountManager.shared.fetchArticles(fetchType)
 	}
 
-	func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		AccountManager.shared.fetchArticlesAsync(fetchType, callback)
+	func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		AccountManager.shared.fetchArticlesAsync(fetchType, completion)
 	}
 
 	func fetchUnreadArticles() -> Set<Article> {
 		return fetchArticles().unreadArticles()
 	}
 
-	func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		fetchArticlesAsync{ callback($0.unreadArticles()) }
+	func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		fetchArticlesAsync{ completion($0.unreadArticles()) }
 	}
 }
diff --git a/Shared/SmartFeeds/StarredFeedDelegate.swift b/Shared/SmartFeeds/StarredFeedDelegate.swift
index 81f05fbf9..000dca8c4 100644
--- a/Shared/SmartFeeds/StarredFeedDelegate.swift
+++ b/Shared/SmartFeeds/StarredFeedDelegate.swift
@@ -23,7 +23,7 @@ struct StarredFeedDelegate: SmartFeedDelegate {
 	let fetchType: FetchType = .starred
 	var smallIcon: IconImage? = AppAssets.starredFeedImage
 
-	func fetchUnreadCount(for account: Account, callback: @escaping (Int) -> Void) {
-		account.fetchUnreadCountForStarredArticles(callback)
+	func fetchUnreadCount(for account: Account, completion: @escaping (Int) -> Void) {
+		account.fetchUnreadCountForStarredArticles(completion)
 	}
 }
diff --git a/Shared/SmartFeeds/TodayFeedDelegate.swift b/Shared/SmartFeeds/TodayFeedDelegate.swift
index 0bd70f653..918e82054 100644
--- a/Shared/SmartFeeds/TodayFeedDelegate.swift
+++ b/Shared/SmartFeeds/TodayFeedDelegate.swift
@@ -21,8 +21,8 @@ struct TodayFeedDelegate: SmartFeedDelegate {
 	let fetchType = FetchType.today
 	var smallIcon: IconImage? = AppAssets.todayFeedImage
 	
-	func fetchUnreadCount(for account: Account, callback: @escaping (Int) -> Void) {
-		account.fetchUnreadCountForToday(callback)
+	func fetchUnreadCount(for account: Account, completion: @escaping (Int) -> Void) {
+		account.fetchUnreadCountForToday(completion)
 	}
 }
 
diff --git a/Shared/SmartFeeds/UnreadFeed.swift b/Shared/SmartFeeds/UnreadFeed.swift
index 053390c4c..b855f5f56 100644
--- a/Shared/SmartFeeds/UnreadFeed.swift
+++ b/Shared/SmartFeeds/UnreadFeed.swift
@@ -65,15 +65,15 @@ extension UnreadFeed: ArticleFetcher {
 		return fetchUnreadArticles()
 	}
 
-	func fetchArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		fetchUnreadArticlesAsync(callback)
+	func fetchArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		fetchUnreadArticlesAsync(completion)
 	}
 
 	func fetchUnreadArticles() -> Set<Article> {
 		return AccountManager.shared.fetchArticles(fetchType)
 	}
 
-	func fetchUnreadArticlesAsync(_ callback: @escaping ArticleSetBlock) {
-		AccountManager.shared.fetchArticlesAsync(fetchType, callback)
+	func fetchUnreadArticlesAsync(_ completion: @escaping ArticleSetBlock) {
+		AccountManager.shared.fetchArticlesAsync(fetchType, completion)
 	}
 }
diff --git a/iOS/MasterFeed/MasterFeedViewController.swift b/iOS/MasterFeed/MasterFeedViewController.swift
index ccbc199dd..127e5d333 100644
--- a/iOS/MasterFeed/MasterFeedViewController.swift
+++ b/iOS/MasterFeed/MasterFeedViewController.swift
@@ -764,20 +764,20 @@ private extension MasterFeedViewController {
 		applyToCellsForRepresentedObject(representedObject, configure)
 	}
 
-	func applyToCellsForRepresentedObject(_ representedObject: AnyObject, _ callback: (MasterFeedTableViewCell, Node) -> Void) {
+	func applyToCellsForRepresentedObject(_ representedObject: AnyObject, _ completion: (MasterFeedTableViewCell, Node) -> Void) {
 		applyToAvailableCells { (cell, node) in
 			if node.representedObject === representedObject {
-				callback(cell, node)
+				completion(cell, node)
 			}
 		}
 	}
 	
-	func applyToAvailableCells(_ callback: (MasterFeedTableViewCell, Node) -> Void) {
+	func applyToAvailableCells(_ completion: (MasterFeedTableViewCell, Node) -> Void) {
 		tableView.visibleCells.forEach { cell in
 			guard let indexPath = tableView.indexPath(for: cell), let node = dataSource.itemIdentifier(for: indexPath) else {
 				return
 			}
-			callback(cell as! MasterFeedTableViewCell, node)
+			completion(cell as! MasterFeedTableViewCell, node)
 		}
 	}
 
diff --git a/iOS/SceneCoordinator.swift b/iOS/SceneCoordinator.swift
index 917677981..9cb6d5ef1 100644
--- a/iOS/SceneCoordinator.swift
+++ b/iOS/SceneCoordinator.swift
@@ -1630,7 +1630,7 @@ private extension SceneCoordinator {
 		
 	}
 
-	func fetchUnsortedArticlesAsync(for representedObjects: [Any], callback: @escaping ArticleSetBlock) {
+	func fetchUnsortedArticlesAsync(for representedObjects: [Any], completion: @escaping ArticleSetBlock) {
 		// The callback will *not* be called if the fetch is no longer relevant — that is,
 		// if it’s been superseded by a newer fetch, or the timeline was emptied, etc., it won’t get called.
 		precondition(Thread.isMainThread)
@@ -1641,7 +1641,7 @@ private extension SceneCoordinator {
 			guard !operation.isCanceled, let strongSelf = self, operation.id == strongSelf.fetchSerialNumber else {
 				return
 			}
-			callback(articles)
+			completion(articles)
 		}
 		
 		fetchRequestQueue.add(fetchOperation)
diff --git a/submodules/RSDatabase b/submodules/RSDatabase
index b2ad9272e..8a574c7dc 160000
--- a/submodules/RSDatabase
+++ b/submodules/RSDatabase
@@ -1 +1 @@
-Subproject commit b2ad9272e8003b0aba3c8c961239663ac501f00b
+Subproject commit 8a574c7dc24156d9d01c6c9fe7d4c9e099c54a96
diff --git a/submodules/RSParser b/submodules/RSParser
index 81c400a76..9e5f5d644 160000
--- a/submodules/RSParser
+++ b/submodules/RSParser
@@ -1 +1 @@
-Subproject commit 81c400a7665309a08414bf43ca5161d90d072501
+Subproject commit 9e5f5d644c1291daf516b9466cb23592374f8e10
diff --git a/submodules/RSWeb b/submodules/RSWeb
index b2dd50f1f..e51306297 160000
--- a/submodules/RSWeb
+++ b/submodules/RSWeb
@@ -1 +1 @@
-Subproject commit b2dd50f1ff2a64c09a543d00bc35c8a66c1fc2b6
+Subproject commit e513062972cd8097179ed39999f327ad29c8a4e1