This thread will list the various casino Redemption Notices.
Regulations vary from state to state, but each state's gaming authority has a process in place that casinos must follow when they decide to no longer allow patrons to cash in their chips or tokens. The most common method is via a Redemption Notice.
The most regulated jurisdiction is Nevada. Casino operators in Nevada are required to publicly post advisements of the discontinuance of chips/tokens for 120 days in advance of the discontinuance. Public advisement is mostly through the newspapers, in the Public Notices section.
In New Jersey, there are no Redemption Notices, because chips/tokens are always redeemable for the life of the Gaming Commission, as each casino operation must post funds, in advance of operation, that will fund pay outs in the event of a collapse, bankruptcy, or other early going-out-of-business event. Both the Playboy and Sands have gone this route.
Many Native American casinos will simply post notices inside the casino that they intend to stop honoring certain chips/tokens on a stated date. Some will just let the incoming rack replace the old one and after a year just stop honoring the old ones. It varies greatly and may or may not have a regulatory feature.
Always be aware of people who are trying to use casino chips as currency. This is illegal, although a common practice, especially within Las Vegas. Without knowing whether the chips have been discontinued, you may be getting scammed.