I completely don't get what the PREFIX and SEPARATOR are good for.
Do they become part of the note uploaded to GC.com? If so, this is the wrong approach as we should not put any additional stuff into the personal note edited by the user. Also we should not put any "c:geo identifiable" markers into GC content at all.
Or ar they just for the test cases? If so, these constants (and the parser routine) shall not exist in the production code. Then they have to live in the test code.