Looking through a lot of the PHP questions, I see a lot of questions that use deprecated features like mysql_query. Usually this ends up with at least 2 comments on the question somewhere along the lines of:
Don't use mysql_* - the functions are deprecated. Use mysqli or PDO instead
How about a "default tag" feature? So basically, they'd work like tags where users with enough karma could create/modify, and then users could hit a "Add Default Tag" link that was shown on a question that needed it. That would bring up a modal with all of the default tags where users could pick a relevant tag.
Would this not lead to a better commenting/discussion on S.O. questions?