Standard DTDs/Templates

Hey,

I am relatively new in the XML field. I am designing a database for a
project on the events recorded from oceans.

Someone told me that there is an international agency that has defined some
standard DTDs/Templates for XML and one should design the database according
to them. My database is storing information obtained from buoys located at
the Gulf of Maine and the information is like salanity at different depths,
wind speed and direction, pressure at different depths etc.

I did some google searching but was not able to find anything related to
this. It would be a great help if you could provide me with a link to the
site where they store such information or the name of the agency or
something helpful.

Thanks and Regards
Parang Saraf
 parang.saraf@gmail.com