What's rule 5?

[Zombie]

I've had an email, that landed in my spam box, stating that I've had a post removed from a thread I've not posted on in months.

The email didn't give any details beyond it contravened rule 5. But I have no idea what that is or where to find the rules. Yes, I have looked for them, I don't know where to start. TBH, I struggle to find my own posts and responses...

TIA.

[BertieWooster]

Rules of posting are here: https://www.pistonheads.com/rules-of-posting