diff --git a/cpdfmanual.tex b/cpdfmanual.tex
index fccb630..7ffd79c 100644
--- a/cpdfmanual.tex
+++ b/cpdfmanual.tex
@@ -1,3 +1,4 @@
+%Document new places one can use -process-struct-trees
 %Document %objnum in -extract-images
 %\DocumentMetadata{lang=en, pdfversion=2.0, pdfstandard=ua-2, pdfstandard=a-4f, testphase={phase-III, title, table, math, firstaid}}
 \documentclass{book}