Well, here's another piece of creative fiction!

[Sentryduty]

In the CDN service I am sure it was recommended or written somewhere, but if so it was never enforced.

Even on live fire, if you forgot your plugs and none were available, it was down to sharing or stuffing cigarette filters in the ears. The show must go on and don't be stupid next time was the way of the way of the world at the time.