WordPress at a glance
action is not described

_wp_put_post_revision action-hook . WP 2.6.0

Fires once a revision has been saved.

Usage

add_action( '_wp_put_post_revision', 'action_function_name_2475' );
function action_function_name_2475( $revision_id ){
	// action...
}
$revision_id(int)
Post revision ID.

Where the hook is called

_wp_put_post_revision()
_wp_put_post_revision
wp-includes/revision.php 312
do_action( '_wp_put_post_revision', $revision_id );

Where the hook is used (in WP core)

Does not used.