we've maintained the set of text header types to use for Purchase Orders in SPRO.
The view that's behind the customizing is V_TTXID_MM_UPD, which is a join of TTXID and TTXIT.
The thing is that we want to retrieve the list of the text header types that we defined in SPRO at runtime (in ABAP) but we don't know where this list is maintained.
I can see the entries in TTXID and TTXIT but those are too many for us. We just defined a subset of them.
What table is the customizing stored into?