Yeah, the rewording proposed by Rafael sounds like the best option to me.

@steveklabnik yeah... those ones are sometimes used out there, but in our docs we either word it in a generic way "Checks whether... Says if..." or else "true" and "false" in regular font. "Truthy/falsey" would be more explicit, but these kind of docs appear frequently and they wouldn't read very naturally.

I should write this in the docs guidelines actually.