Postal codes in the Cayman Islands are used by the Cayman Islands Postal Service to route inbound mail to groups of Post Office Boxes in the country. A postal code typically consists of an island code, a hyphen separator, and a section code.
There are only three island codes: KY1 for Grand Cayman, KY2 for Cayman Brac, and KY3 for Little Cayman. Each of these is subdivided into section codes according to which local post office handles a particular group of boxes.
A single sheet portable document is available from CIPS listing all post codes in the archipelago.
References
Postal codes in the Cayman Islands Wikipedia(Text) CC BY-SA