IFC tags

I would like to learn abot parametres to IFC “instructions” within IFC file. E.g. “IFCCARTESIANPOINT” - here it’s clear that the instruction takes one point of x, y and z coordinates. But what about “IFCGEOMETRICREPRESENTATIONSUBCONTEXT”? I’d like to understand meaning of each parameter, its kind (point, array, enum, string, …), its “optionality” and so on. Where should I find some study stuff? Or is there a something like “Guide to IFC File (Format) for Beginners”?
Best regards,


Have a look at

For the schema, see the attributes table at e.g:


^ that is the 4.3 version of the schema.