Breaking up category to list departments more clearly

About 4 or 5 years ago, Script Supervisors/Continuity were listed under miscellaneous. And then they were changed to be listed under their own department.

How did this come about? And how can it be done for another department?

Anyone know the history behind it?

In the UK the Script Supervisor was historically part of the Camera Department. But never listed by IMDB as so.