The $ViewFormat item in views and folders contains an ever-expanding list of structures, most of which have variable data. The C API documentation, however, mostly stopped bothering keeping up to date - half of the references stop around R4, while other parts at least give nods to components added in R6, though give no indication of what the variable data for each column is, that resource links are CDRESOURCE structures, where VIEW_TABLE_FORMAT5 might appear, and so forth.
The example C file stops around R3, which is not helpful.
The structures themselves seem to be mostly documented, though the NSF-based docs often lag behind the C headers, and the headers in turn reference other files not included in the public SDK.
This appears to have been a problem for just shy of 20 years now: https://ds_infolib.hcltechsw.com/ldd/nd6forum.nsf/DateAllFlatweb/F0DF11AFF43900C385256CAA0032C9ED?OpenDocument