With revision 39077, much of the implementations of the GRAMMAR functionality have been moved from MediaWiki proper to a more appropriate extension. While that is undoubtedly a good thing, there will be a problem with multiple such extensions, or in cases of laguages implementing more general GRAMMAR routines later, e.g. rule based ones.
In order for those to coexist, both a hook-type access to the various GRAMMAR routines would be advisable, and ways allowing them to priorize themselves before being called.
I have not inspected the R39077 changes in depth. Maybe I missed that there is such a mechanism already. In that case, I apologize for bothering you.
Version: unspecified
Severity: enhancement