<* > pointer based parameters have no problem, as Clarion assumes the absense of a parameter can be represented with a 0 pointer, but with simple value parameters, extra data is needed to support OMITTED.
Here there is an example app based on both prototypes. With <> on simple value parameters it crashes, with = 0 it works.
Also there is an screen capture of Clarion Debugger where it can be seen the extra PUSH 1’s to the stack when using <>
TestOmitParam.clw (1,4 KB)