WordPress at a glance
filter is not described

format_to_edit filter-hook . WP 1.2.0

Filters the text to be formatted for editing.

Usage

add_filter( 'format_to_edit', 'filter_function_name_557' );
function filter_function_name_557( $content ){
	// filter...

	return $content;
}
$content(string)
The text, prior to formatting for editing.

Where the hook is called

format_to_edit()
wp-includes/formatting.php 2339
$content = apply_filters( 'format_to_edit', $content );

Where the hook is used (in WP core)

Does not used.