Bring the thunder and reap the whirlwind.
Task Force Echelon is the name given to the group of starships immediately under the command of Starfleet Intelligence. Officially, the task force does not exist, and no records of it are to be found in any Federation database. Most of Starfleet maintains that there is no such intelligence task force.
Starships that belong to Task Force Echelon often carry classified equipment or have undergone extensive refits in order to perform intelligence-based missions. Often these ships will also have additional “silent running” or covert operations modes, and some are rumored to be equipped with cloaking devices.