Sounds reasonable. Let's just settle for enough SWI-PL keywords to provide a common denominator between the Vim and VS Code implementations. Type specifiers are unique to Visual Prolog and could be better implemented by a tags parser anyway. Serious users would expect their custom types to be styled the way typedef'd structs currently are in C and family.
So should I merge the vim and VS code keywords? Right now it's the VS code keywords only.