In reply to Bluebird: safety chain. Insurers would like you to use as much CW equipment as possible to insure that fault is easier to place and all draws are then also maintained by the CW.
But even that differs depending on insurer, each insurer has different rules. Insurance audits are as annoying as health and safety audits in bars and restaurants one day you lose points for not keeping the ice well scoop in sanitiser the next day you lose points for doing it.