Is anyone familiar with Omnis Studio's data files? I have some Omnis data I'm converting and I can't locate the foreign keys on child tables. Are these hidden somehow in Omnis?

I've looked at the files through the Omnis ODBC driver and in Omnis Studio 4.2. In neither can I find the foreign keys. Am I missing some additional files that hold RI information or something? All I have are the .DF1 files.

TIA