I have an element that can be one of two things, either:

  < string >

Or

  <>

So I modeled this as a choice.  For the first choice, I made it a string with < and > being the initiator and terminator.  Works great.

For the second choice, I also made it a string with < and > being the initiator and terminator, and I set the length kind to explicit and the length to 0.  That seems obvious enough.  But, alas, that causes errors in parsing.  Nothing I do for this seemingly simple construct works.  There must be some design pattern here that I am missing.

Ideas?

TIA