For a couple weeks, moderators have been declining not an answer flags on link-only answers:
declined - Please don't flag link only answers as 'not an answer': When should you decide whether to flag a posted answer as Not an answer?
Image from Lucifer's comment:
If moderators are just declining these flags and requesting a "Link only answer" custom flag, shouldn't "Link only answer" be a permanent (diamond) flag option?
Edit: There seems to be some confusion (credit Doorknob) amongst moderators about this. Could we please get a clarification about how these are supposed to be used?