A strumpet is a sufficient witness to a happening in a brothel.

Explanation

A witness is competent to testify about events occurring in a place she frequents, regardless of her character — the law takes testimony where it can find it.

Where this applies

• A witness who frequents a shady location saw something happen there and wants to testify.
• They're trying to disqualify my witness because of where the events took place.
• The only person who saw what happened at that location is someone with a questionable reputation.