If the whole purpose of storing flags names is to output readable debug info I think it's better to have a single separate function

that takes flags combination and returns static buffer pointer with a name. This way it will need just to append after bitwise 'and' check.

+  /* tests for ITextDocument::Open */
+  for(; tomNunSingle >= 0; tomNunSingle--)

Do you really need to go from the tail here?