Manual error? php.ini

http://www.php.net/manual/en/configuration.directives.php claims that the upload_max_filesize directive accepts an integer (with a handy link to the definition of integer). http://www.php.net/manual/en/language.types.integer.php defines an integer as "a number of the set Z = {..., -2, -1, 0, 1, 2, ...}", and that "integers can be specified in decimal (10-based), hexadecimal (16-based) or octal (8-based) notation, optionally preceded by a sign (- or +)". However, the default upload_max_filesize is "2M", where M (I assume) signifies "*1048576". The same goes for a few other directives. Can anyone point me to where the number format for upload_max_filesize is defined?