Redesign of the Map Reference Set formats

Hi everyone

Please find below a proposal for redesigning the map reference sets to support maps in either direction:

https://docs.google.com/document/d/14bmRaVQYI7-Kz2EPgv00muGqdO6wRrMycCPCJqp5W2s

If you could please review before the TRAG meeting and provide any feedback that would be great?  We can then discuss any issues in the next TRAG meeting in October.

Thanks very much

Andrew