diff --git a/Frameworks/RSParser/Feeds/JSON/JSONFeedParser.swift b/Frameworks/RSParser/Feeds/JSON/JSONFeedParser.swift
index a31f1deb5..4ec70f628 100644
--- a/Frameworks/RSParser/Feeds/JSON/JSONFeedParser.swift
+++ b/Frameworks/RSParser/Feeds/JSON/JSONFeedParser.swift
@@ -111,7 +111,10 @@ private extension JSONFeedParser {
 		let dateModified = parseDate(itemDictionary["date_modified"] as? String)
 
 		let authors = parseAuthors(itemDictionary)
-		let tags = itemDictionary["tags"] as? [String]
+		var tags: Set<String>? = nil
+		if let tagsArray = itemDictionary["tags"] as? [String] {
+			tags = Set(tagsArray)
+		}
 		let attachments = parseAttachments(itemDictionary)
 
 		return ParsedItem(syncServiceID: nil, uniqueID: uniqueID, feedURL: feedURL, url: url, externalURL: externalURL, title: title, contentHTML: contentHTML, contentText: contentText, summary: summary, imageURL: imageURL, bannerImageURL: bannerImageURL, datePublished: datePublished, dateModified: dateModified, authors: authors, tags: tags, attachments: attachments)
@@ -140,14 +143,14 @@ private extension JSONFeedParser {
 		return RSDateWithString(dateString)
 	}
 
-	static func parseAttachments(_ itemDictionary: JSONDictionary) -> [ParsedAttachment]? {
+	static func parseAttachments(_ itemDictionary: JSONDictionary) -> Set<ParsedAttachment>? {
 
 		guard let attachmentsArray = itemDictionary["attachments"] as? JSONArray else {
 			return nil
 		}
-		return attachmentsArray.flatMap { (oneAttachmentObject) -> ParsedAttachment? in
+		return Set(attachmentsArray.flatMap { (oneAttachmentObject) -> ParsedAttachment? in
 			return parseAttachment(oneAttachmentObject)
-		}
+		})
 	}
 
 	static func parseAttachment(_ attachmentObject: JSONDictionary) -> ParsedAttachment? {
diff --git a/Frameworks/RSParser/Feeds/JSON/RSSInJSONParser.swift b/Frameworks/RSParser/Feeds/JSON/RSSInJSONParser.swift
index a37bf1770..8a510f711 100644
--- a/Frameworks/RSParser/Feeds/JSON/RSSInJSONParser.swift
+++ b/Frameworks/RSParser/Feeds/JSON/RSSInJSONParser.swift
@@ -141,23 +141,21 @@ private extension RSSInJSONParser {
 		return Set([parsedAuthor])
 	}
 
-	static func parseTags(_ itemDictionary: JSONDictionary) -> [String]? {
+	static func parseTags(_ itemDictionary: JSONDictionary) -> Set<String>? {
 
 		if let categoryObject = itemDictionary["category"] as? JSONDictionary {
 			if let oneTag = categoryObject["#value"] as? String {
-				return [oneTag]
+				return Set([oneTag])
 			}
 			return nil
 		}
 		else if let categoryArray = itemDictionary["category"] as? JSONArray {
-			return categoryArray.flatMap{ (categoryObject) in
-				return categoryObject["#value"] as? String
-			}
+			return Set(categoryArray.flatMap{ $0["#value"] as? String })
 		}
 		return nil
 	}
 
-	static func parseAttachments(_ itemDictionary: JSONDictionary) -> [ParsedAttachment]? {
+	static func parseAttachments(_ itemDictionary: JSONDictionary) -> Set<ParsedAttachment>? {
 
 		guard let enclosureObject = itemDictionary["enclosure"] as? JSONDictionary else {
 			return nil
@@ -175,6 +173,6 @@ private extension RSSInJSONParser {
 
 		let type = enclosureObject["type"] as? String
 		let oneAttachment = ParsedAttachment(url: attachmentURL, mimeType: type, title: nil, sizeInBytes: attachmentSize, durationInSeconds: nil)
-		return [oneAttachment]
+		return Set([oneAttachment])
 	}
 }
diff --git a/Frameworks/RSParser/Feeds/ParsedAttachment.swift b/Frameworks/RSParser/Feeds/ParsedAttachment.swift
index e3d369659..29520033a 100644
--- a/Frameworks/RSParser/Feeds/ParsedAttachment.swift
+++ b/Frameworks/RSParser/Feeds/ParsedAttachment.swift
@@ -8,14 +8,15 @@
 
 import Foundation
 
-public struct ParsedAttachment {
+public struct ParsedAttachment: Hashable {
 
 	public let url: String?
 	public let mimeType: String?
 	public let title: String?
 	public let sizeInBytes: Int?
 	public let durationInSeconds: Int?
-
+	public let hashValue: Int
+	
 	init(url: String?, mimeType: String?, title: String?, sizeInBytes: Int?, durationInSeconds: Int?) {
 
 		self.url = url
@@ -23,5 +24,23 @@ public struct ParsedAttachment {
 		self.title = title
 		self.sizeInBytes = sizeInBytes
 		self.durationInSeconds = durationInSeconds
+		
+		var stringToHash = ""
+		stringToHash += url ?? ""
+		stringToHash += mimeType ?? ""
+		stringToHash += title ?? ""
+		var h = stringToHash.hashValue
+		if let sizeInBytes = sizeInBytes {
+			h = h ^ sizeInBytes.hashValue
+		}
+		if let durationInSeconds = durationInSeconds {
+			h = h ^ durationInSeconds.hashValue
+		}
+		self.hashValue = h
+	}
+	
+	public static func ==(lhs: ParsedAttachment, rhs: ParsedAttachment) -> Bool {
+		
+		return lhs.hashValue == rhs.hashValue && lhs.url == rhs.url && lhs.mimeType == rhs.mimeType && lhs.title == rhs.title && lhs.sizeInBytes == rhs.sizeInBytes && lhs.durationInSeconds == rhs.durationInSeconds
 	}
 }
diff --git a/Frameworks/RSParser/Feeds/ParsedItem.swift b/Frameworks/RSParser/Feeds/ParsedItem.swift
index 1d90f47a7..ee37ddbe3 100644
--- a/Frameworks/RSParser/Feeds/ParsedItem.swift
+++ b/Frameworks/RSParser/Feeds/ParsedItem.swift
@@ -24,11 +24,11 @@ public struct ParsedItem: Hashable {
 	public let datePublished: Date?
 	public let dateModified: Date?
 	public let authors: Set<ParsedAuthor>?
-	public let tags: [String]?
-	public let attachments: [ParsedAttachment]?
+	public let tags: Set<String>?
+	public let attachments: Set<ParsedAttachment>?
 	public let hashValue: Int
 	
-	init(syncServiceID: String?, uniqueID: String, feedURL: String, url: String?, externalURL: String?, title: String?, contentHTML: String?, contentText: String?, summary: String?, imageURL: String?, bannerImageURL: String?, datePublished: Date?, dateModified: Date?, authors: Set<ParsedAuthor>?, tags: [String]?, attachments: [ParsedAttachment]?) {
+	init(syncServiceID: String?, uniqueID: String, feedURL: String, url: String?, externalURL: String?, title: String?, contentHTML: String?, contentText: String?, summary: String?, imageURL: String?, bannerImageURL: String?, datePublished: Date?, dateModified: Date?, authors: Set<ParsedAuthor>?, tags: Set<String>?, attachments: Set<ParsedAttachment>?) {
 
 		self.syncServiceID = syncServiceID
 		self.uniqueID = uniqueID
@@ -51,6 +51,7 @@ public struct ParsedItem: Hashable {
 	
 	public static func ==(lhs: ParsedItem, rhs: ParsedItem) -> Bool {
 		
+		// TODO: compare all properties.
 		return lhs.hashValue == rhs.hashValue && lhs.uniqueID == rhs.uniqueID && lhs.feedURL == rhs.feedURL
 	}
 }