Cryptologic Technician (CT) is a United States Navy enlisted rating or job specialty. The CT community performs a wide range of tasks in support of the national intelligence-gathering effort, with an emphasis on cryptology and signal intelligence related products. Most CT personnel are required to obtain and maintain security clearances. Due to the highly classified and secure work environment requiring very restricted access, it is not always possible to share resources with other commands, leading to their shipboard nickname, "spooks". Almost every detail surrounding the CT world from administration to operations to repair requires dedicated technicians with appropriate security clearances (this accounts for the many branches of the CT rating, i.e. CTI, CTM, CTN, CTO, CTR, CTT). The contribution of an individual CT will depend upon the branch or career area.