WordPress at a glance
filter is not described

sanitize_file_name_chars filter-hook . WP 2.8.0

Filters the list of characters to remove from a filename.

Usage

add_filter( 'sanitize_file_name_chars', 'filter_function_name_1975', 10, 2 );
function filter_function_name_1975( $special_chars, $filename_raw ){
	// filter...

	return $special_chars;
}
$special_chars(array)
Characters to remove.
$filename_raw(string)
Filename as it was passed into sanitize_file_name().

Where the hook is called

sanitize_file_name()
wp-includes/formatting.php 1787
$special_chars = apply_filters( 'sanitize_file_name_chars', $special_chars, $filename_raw );

Where the hook is used (in WP core)

Does not used.