screenshot from ao3 of a search for the tag: program butt appreciation.

This tag belongs to the Additional Tags Category.
Parent tags (more general):
Tron: Evolution

…

…You ever encounter a tag that is a “parent” of a whole ton of tags that nobody even knows about

a real Zeus of a tag

“Tron: Evolution” is one of these.

Months ago I made a Baby Got Back music video about the difference in butt aesthetics between Tron (1982) and Tron (Uprising).

Tags included “slightly implied Flynn/Tron,” “slightly implied one-sided Beck/Tron” and “program butt appreciation.” None of these tags have any other hits besides that one music video.

and yet, for all of these– and really for pretty much all uncommon Tron tags I use (which are mostly 1982-related and pre-Evolution)– AO3 gives the additional information: “Parent tags (more general): Tron: Evolution.”

How did Tron Evolution become the parent tag of all that?
What even are parent tags?

Is it like parent processes and child processes, in programming? (“Well, you see, children, when one program forks a whole lot…”)