Gentleman’s agreement
Describes an arrangement or understanding which is based upon the trust of both or all parties, rather than being legally binding.
Why it matters
Whilst not a particularly contentious term, especially when a man is accurately involved, this is an example where 'man' is used as a default gender to describe something. Unless useful to specify gender, using gender neutral phrases help set a broader welcoming tone in the language that surrounds us.
Instead try saying:
Further External Reading Link