(Define the problem you are seeking to solve.)
(Specify the requirements that a proposal should meet.)
(Use this space for data gathering, status quo, proposals, other considerations etc.)
See https://www.mediawiki.org/wiki/Requests_for_comment/Parser_function_and_tag_tracking
Note that @mobrovac, @Milimetric and I have been discussing a next generation dependency tracking service for a while. Tracking the usage of parser functions seems like another use case for such a service.
We still don't have a great writeup (coming Very Soon Now), only an outdated brain dump of mine. But looking into this is part of the platform team's annual goals, so let's make sure this is coordinated.
@Legoktm wrt the RFC process: this is marked as "under discussion" for now. Let us know if you think this could benefit from a discussion on IRC, or whether you feel this could move to a Last Call right away.