What are the following documents about aircraft maintenance?
A service bulletin is a document that the manufacturer of an aircraft issues directly to operators of related aircraft. It mandates some maintenance / replacement / check activities. 

A rapid revision is a change to the maintenance documents, that is not released officially according to normal procedures, yet.

A non conformation report is any discrepancy found in the aircraft / system such that the related system does not look / operate / behave / function as expected. This document is mostly a form that the ground crew / technicians / pilots generate.

Disclaimer: these are general information and details would change depending on whether the aircraft is a civil or military one, and the certification type. This answer is written in the perspective of military aircraft, for general knowledge.