Acts on text which is about to be edited.
Unless $richedit is set, it is simply a holder for the 'format_to_edit' filter. If $richedit is set true htmlspecialchars will be run on the content, converting special characters to HTML entities.
<?php format_to_edit( $content, $richedit ) ?>
Since: 0.71
format_to_edit() is located in wp-includes/formatting.php
.