USA Karate rules are found here. This page includes the online test which officials should take before going to the referee seminar (before a tournament they are planning on working at).
The World Karate Federation has new rules starting January 2015, found at this link, which officials should familiarize themselves with, because the USA rules will likely change to follow the world rules.
We will be posting new information for you to learn some of the aspects of judging and scorekeeping at times. This first video and the accompanying worksheets will show you how repecharge is performed. Please watch on YouTube and full screen and high resolution to be able to read the words on the screen and follow along.
These worksheets can be printed out and worked on without the stress of a competition. They show many, common situations which come up in local tournaments.