Caid has no special sumptuary laws; however, it does recognize those items of regalia restricted by the SCA.
An "unadorned chain" is a loop of chain worn around the neck that does not have any medallions or other items dangling from it. These chains are reserved to members of the Chivalry, as designated by SCA-wide sumptuary law.
The words of the knighting ceremony used in Caid refer to the symbolism of the chain: "Take now this chain, and let its weight ever remind you of the fealty you have sworn."
Since the chain explicitly represents that fealty has been sworn, often knights will remove their chains at Coronation, after the retiring King and Queen have stepped down, and don them again after they have sworn fealty to the new King and Queen. That action is a choice made by individual knights, based on their understanding of how fealty in the Society works. There are many different views on that, which is a good topic for conversation, but not for this article.
In some reigns, the Crown has specifically given permission for all Peers who have sworn fealty to wear an unadorned chain as symbol of that fealty. This permission is only for the duration of that reign, or until rescinded by the Crown.
Squires in Caid do not wear unadorned chains of any color. In some kingdoms, the gold chain represents knights, and a squire who is in fealty to their knight is permitted to wear a silver chain. However, this custom is not followed in Caid.