Syntax:
HELP 'search_string'

The HELP statement returns online information from the MySQL Reference
manual. Its proper operation requires that the help tables in the mysql
database be initialized with help topic information (see
http://dev.mysql.com/doc/refman/5.5/en/server-side-help-support.html).

The HELP statement searches the help tables for the given search string
and displays the result of the search. The search string is not case
sensitive.

URL: http://dev.mysql.com/doc/refman/5.5/en/help.html

