Board Thread:Support Requests - Getting Technical/@comment-5558012-20141026165705/@comment-4018164-20141026192940

Seems like it requires an extionsion to work (which can be requested via Special:Contact/general). It appears in Special:Version in some wikis that i checked, so it's probably available by default in Wikia, to answer your second question.

To answer your first question,  will match any text that is jp e g and cotains 0 or 1 occurations of the matching e (marked in red here).

For your third question, try (will not affect video file names): File\:.{0,6}\.[^\.]+
 * 1) make sure that all files have at least 7 characters in their name

File\:.*(tumblr|screenshot|moreWordsHere).* The patterns in the extension are case-insensitive, so you don't need to use uppercase.
 * 1) file name blacklist (i got this simplified example from MediaWiki's MediaWiki page for that)

In addition, i believe that if you want to block titles that contain characters in them that are used to affect the patterns (such as \, ?, *), they should be escaped by putting a slash (\) before them.

In addition, you might want to check some patterns from MediaWiki's MediaWiki page for the blacklist.