WordPress at a glance
filter is not described

ms_user_row_actions filter-hook . WP 3.2.0

Filters the action links displayed under each user in the Network Admin Users list table.

Usage

add_filter( 'ms_user_row_actions', 'filter_function_name_8700', 10, 2 );
function filter_function_name_8700( $actions, $user ){
	// filter...

	return $actions;
}
$actions(array)
An array of action links to be displayed.
Default: 'Edit', 'Delete'
$user(WP_User)
WP_User object.

Where the hook is called

WP_MS_Users_List_Table::handle_row_actions()
wp-admin/includes/class-wp-ms-users-list-table.php 454
$actions = apply_filters( 'ms_user_row_actions', $actions, $user );

Where the hook is used (in WP core)

Does not used.