Dave, I'll do both. When I post a new code that I've found, I'll be sure to include it in a new post as well as editing the "master list." Obviously, if someone else posts a code suggestion then I won't need to add an additional post but will just add it to the master list. I want to try to maintain an up-to-date, alphabetical master list in the original post so that it is easy to find all the current codes. Some people may find this thread from search engines and I don't want them to have to slog through endless posts of expired codes and comments only to find that the code they want is no longer valid. I'd rather their introduction to ATP be a happy and helpful one that will make them want to stay and recommend it to others!
Becky, great suggestion! The company names in the master list are now hyper-linked!
Thank you all for the ideas and encouragement!