Rules of Regency England
1. Cannot dance more than twice with a gentleman, three times with the same gent is a scandal
2. Cannot be alone with a gentleman
3. Cannot show ankles
4. Cannot have hair let down in public
5. Married couples are allowed to conduct discreet affairs, preferably after producing the required heir(s).
6. Cannot hold a lady's hand for more than 6 seconds (in greeting)
References from Potent Pleasures & Enchanting Pleasures by Eloisa James