Stanford Parser tags

This reference looks to have an extensive list - not sure if it is complete or not.

Specifically, it lists the ones you're asking about as:

SBARQ - Direct question introduced by a wh-word or a wh-phrase. Indirect 
        questions and relative clauses should be bracketed as SBAR, not SBARQ.
SQ    - Inverted yes/no question, or main clause of a wh-question, 
        following the wh-phrase in SBARQ.