Dear Mark and Dave I agree with Dave's answers. If two conventions are used together, it is the responsibility of the data-writer to guarantee that the metadata supplied is consistent if there are any overlaps in meaning. A particular case of that is if the two conventions define attributes with the same names. It has been suggested that conventions could signal their own name-spaces e.g. CF attributes could all be prefixed with "cf_" (like the cf_role attribute, which has been introduced in the new CF section 9). That could help with preventing collisions of namespaces, but
* it would be cumbersome for writers of files that adhere to only one convention, which is the usual case, and awkward for programs that read files, since they would have to check for every attribute by two different names (with and without the prefix, considering all the data that already exists without prefixes). * it doesn't help if the two conventions are inconsistent in their metadata, whether or not they use similarly named attributes, and this is the more serious problem, I would argue. Therefore I don't think this is really a magic solution to get rid of the potential difficulty. Rather, the writers of conventions have to be aware of other netCDF conventions that might be used with theirs, and try to use ones that already exist instead of defining new ones for a given purpose. Best wishes Jonathan _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata