Using DOA 4.0.6, Delphi 6.

What is the best way to indentify what version of the Oracle Client is in use at runtime?

I am looking at the booleans in OracleCI but don't see any 10g references in the help file. Are there any 10g changes in OracleCI? Would you consider it reliable to deduce the Oracle version based on the OCI functions available (ie, OCI80 but not OCI81 must mean Oracle 8.0.x installed)? Is there a way to get a more specific rev number out of OCI.DLL?