Wikipedia
.cym is a GeoTLD reserved for eventual assignment to the Cayman Islands. The primary top-level domain used by the Cayman Islands is .ky. The Islands already have the international three letter code, CYM. ICANN plans to increase the number of generic top-level domains, and it is through this process that a .cym top-level domain might be awarded.
The Cayman Islands were previously in competition with Wales over use of the top-level domain. A campaign named "dot.CYM", not overly supported at government level, sought to have the .cym suffix for websites concerning Wales , the Welsh language and Welsh culture. However, .cym was eventually assigned to the Cayman Islands because ICANN's policy states that new applications for 3-letter domains will not be accepted if they match existing ISO 3-letter codes. Wales was eventually granted the domain .cymru.