The Tables contain the data in the database. They are organized in 
columns and rows. 
Here you will be shown the names of these columns, their
data type, the data type size, the unit, a short description, a default 
value (if set), and the Unified Content Descriptor. The last one is a 
categorization of any parameter present in a column of a table or catalogue 
in a predefined scheme (see the UCD page at CDS). 
Also a description of the table is given, and a list of the required 
constraints, ie. the primary key and key references.
Indexed variables are higlighted.
Some attributes have a 
image. This indicates that there is some more information in a small 
JavaScript tooltip window. This will appear if you hover with your mouse over 
this image or the attribute itself.
The 
 image shows that there is extended information on this attribute in the glossary. 
Click on the image or the attribute itself to go to the corresponding glossary
entry.
If an attribute is derived directly from a FITS keyword the keyword is given in {...}.