ethics gifts

Can someone please summarize at a high level rules pertaining to Ethics and gifts. When is disclosure required, written permission required , etc? For example, token gifts require _____?

all gifts must be disclosed. only token gifts are acceptable. only get on the corporate jet if commercial transportation is not available.

do any gifts require written permission then? What requires written permission vs just disclosure?

Gifts from clients OK with disclosure, because those gifts are not competing with your primary income. If anything they’re supplementing it.