For questions asking for tips on a specific piece of code, to make it a better answer to a programming challenge that is on-topic on this site. Tag [tips] questions with other appropriate tags, such as [python][code-golf] or [king-of-the-hill].
These questions are asking for tips on some language. Usually, this is for helpful tips and tricks to golf more effectively with a particular language, but this tag has also been used for questions regarding constructing golfing languages.
This tag is also used for questions which ask for specific advice in reducing a particular piece of code further (in the given language).