ETSS are DoD military and civilian personnel technically qualified to provide advice, instruction, and training in the installation, operation, and maintenance of weapons, equipment, and systems. ETSS are attached to an overseas Security Cooperation Organization (SCO) rather than assigned, and they are carried on the Joint Table of Distribution, but are not provided as an augmentation to the SCO staff. ETSS may be provided for overseas assignments for periods of up to but not exceeding one year, unless specifically approved by DSCA.