I found 2 occurrences in c-c: mail/base/content/messageWindow.xul mail/base/content/messenger.xul From studying other source files it seems the "#filter substitution" line does not need to be on the first line of a file. The <?xml?> header not being in the first line of the file causes my text editor not identify the file as XML and not applying proper syntax highlighting. The fix seems to be a more correct way than just forcing the editor to treat all .xul files as xml.
Created attachment 683295 [details] [diff] [review] patch
Comment on attachment 683295 [details] [diff] [review] patch Looks fine