Order of elements in standard.osc

In the standard.osc file, Enums are defined after the Structs but some structs use enums as properties.

For example:
In the standard.osc file, enum crossing_marking is defined at line 446 but first time used/referenced as a property type at line 256
Similarly behavioral_model is defined on line 351 with a bm_engine member, and the bm_engine is defined declared right after on line 354 (see attached image)