PHP Manual
Function Reference
Variable and Type Related Extensions
Filter
Types of filters
Validate filters
Sanitize filters
Other filters
Filter flags
Sanitize filters
Filter flags
Types of filters
PHP Manual
Other filters
List of miscellaneous filters
ID
Name
Options
Flags
Description
FILTER_CALLBACK
"callback"
callable
function or method
All flags are ignored
Call user-defined function to filter data.