MYSQL int(M) Meaning

In many databases, when you see something like int(11), you would expect 11 to be the maximum size of the field but for some reason┬áthe MySQl folks thought that was too intuitive so they decided to change it. In MySQL when you something like int(M), M stands for “Maximum Display Size”.

"M indicates the maximum display width for integer types. The maximum legal display width is 255."

Reference:
Mysql Websites
http://dev.mysql.com/doc/refman/5.0/en/numeric-type-overview.html

Other Resources
http://www.dbforums.com/mysql/1624054-int-m-mysql-what-does-m-mean.html