Use this tag when examining what is on-topic or off-topic, and why, and how to deal with off-topic questions.
on-topic (or scope) is used to define what is pertinent to discussion. Generally, the scope determines what the site is about. Issues arising from on-topic might have to do with whether a certain question is on-topic or not, but also can be used to evaluate whether an entire topic should be up for discussion.
For current officially on-topic subjects on Cross Validated Stack Exchange, visit the help center page. To express your opinion with regards to community standards to help guide future iterations of the community standards please visit the question that serves as clearinghouse for these types of issues
Reference: adapted wiki from Meta Stack Exchange site.