Define.xml Origin values

I was wondering if there is a specified list (or codelist) of values that go into the origin of variables.  So for ADaM it will most likely be either be Assigned, some SDTM variable or Derived. For SDTM there could be a wider range of possibilities. Most probably will be CRF Page(s) ### or Assigned. There are a few Derived fields such as baseline flags and --DY variables.  I've also used EDT (External Data Transfer) for labs and ECGs that are not collected on the CRF. The domains I'm finding tricky are the TDMs and more recently DV.  For a variable like TATRANS, I assume you could use Assigned as the origin but what about Protocol? Is that a valid origin? And for DV, if the data came directly from the sponsor in a spreadsheet would you say EDT or Sponsor or Sponsor Defined?  I haven't been able to locate anything that would point me to one over the other and the issue I'm having is I could justify any of them.  I also have noticed the current define.xml validator portion of OpenCDISC does not check the value of the origin field. There are some additional important checks that I just think are missing. For instance to use the --DY example again, if Derived is my origin then I should always have a description of the algorithm in the @ItemDef/Comment field.

Thoughts and comments appreciated.