Currently most of the tag related functions are fragmented over the whole application. Only for the internal content tags most code is centralized in the editor_Models_Segment_InternalTag class.
Same concept should be used for all our internal tags (MQM, Term Tags).

One goal is to provide the same interface for all tag types:
mqm tags, term tags and content tags extend abstract tag.
The abstract tag class defines the interface for commonly used methods: strip, replace etc.

Another general class internal tag should provide a similar interface to malke bulk operations, example:
generalTag->strip(string, MQM|term) → this leaves content tags