*(2.2) A UCD is a semantic type, not an instance. It is semantically
*different from a Name.
I think this is the key point and absolutely correct. UCDs also don't specify units or data type (i.e. real, string, integer) etc. To specify a column one would need Name, semantic type (UCD), units, and data type. This is all pretty obvious in VOTable already.
The VO needs to solve the problem of column-specification because we want the software to know what to without us. However, shoving this inside UCDs is wrong and indeed dangerously confusing. Don't mess with the UCDs !
This doesn't answer the question of what we do or don't put in Registries, just that distorting UCDs aint the answer anyway.
andy l Received on 2003-09-26Z15:56:11