The UCD resolver tries to guess good UCDs based on your (English)
input. To do this, it tries a naive Bayesian classification against
the descriptions given in Vizier. This, in turn, means that you will
have to carefully review the suggestions and their descriptions
whether they actually match your description, particularly if the data
you are describing does not frequently occur in Vizier.
Thanks to Vizier for providing us with their UCD vs. Column