Baez's law is the principle that fundamental discoveries are named after the person who made them famous, not the person who made them first, and these are often not the same person.
Baez's law is not due to John Baez. It is only named after him, in accordance with itself. It is also called the Matthew effect, after Matthew 25:29. It is a variant of Arnold’s law, which also applies to itself.
There are several more already on the nLab; they just don’t link here yet.