Manual:Protected titles table

Contains protection of non-existant pages, the list of protected pages can be found at Special:Protectedtitles.

DESCRIBE protected_titles; in version 1.12 gives the following: ++--+--+-+-+---+ ++--+--+-+-+---+ ++--+--+-+-+---+
 * Field         | Type             | Null | Key | Default | Extra |
 * pt_namespace  | int(11)          | NO   | PRI |         |       |
 * pt_title      | varchar(255)     | NO   | PRI |         |       |
 * pt_user       | int(10) unsigned | NO   |     |         |       |
 * pt_reason     | tinyblob         | YES  |     | NULL    |       |
 * pt_timestamp  | binary(14)       | NO   | MUL |         |       |
 * pt_expiry     | varbinary(14)    | NO   |     |         |       |
 * pt_create_perm | varbinary(60)   | NO   |     |         |       |