Mousing over any column name shown in link font will provide more information on the data it contains

There is a window at the bottom of the page where you can entery SQL queries and view the results in a number of formats

ATOM_SITES_ALT_GEN
Data items in the ATOM_SITES_ALT_GEN category record details about the interpretation of multiple conformations in the structure.
Field	Type	Null	Key	Default	Extra
atom_sites_alt_gen_key	int(11)	NO	PRI
entry_key	int(11)	NO	MUL
alt_id	varchar(255)	YES
alt_key	int(11)	YES
ens_id	varchar(255)	YES
ens_key	int(11)	YES

Enters your SQL query (only SELECT, SHOW and DESCRIBE supported):

Note: Only SELECT, SHOW or DESCRIBE queries can be performed, any other command will generate an error