UCD Query
The Unified Content Descriptor (UCD) is a formal vocabulary
astronomical data that is controlled by the International Virtual
Observatory Alliance (IVOA). The vocabulary is restricted in order to
avoid proliferation of terms and synonyms, and controlled in order to
avoid ambiguities as far as possible. It is intended to be flexible,
so that it is understandable to both humans and computers. UCDs
describe astronomical quantities, and they are built by combining
words from the controlled vocabulary.
The data List of UCD obtained from ucd1p-words-20070402.txt
(http://cdsweb.u-strasbg.fr/UCD/).