In 2267, the USS Enterprise received a false distress call that supposedly came from the Dierdre, which was under attack by a Klingon ship. The distress call was in fact sent by the Klingons in an attempt to lure the Enterprise away from Capella IV during Captain Kirk's attempt to negotiate for Federation mining rights there.
According to the distress call, the Dierdre was under heavy attack from Klingon vessels; two ships in their convoy were already damaged. Once the freighter's last reported position was reached, the Enterprise's sensors found no debris, residual particles, or residual traces. Chief Engineer Scott, commanding the ship due to the absence of Kirk and Spock, pulled the microtapes of the call and realized that the captain of the Dierdre had called the Enterprise by name – something unlikely to occur, since there is little chance a freighter captain would know the Enterprise had been assigned to that sector. Scotty remained long enough to be certain, and then set a course back for Capella IV. Almost immediately, a new distress call was received, this time from the USS Carolina, lending credence to the fact that the distress call was fraudulent. (TOS: "Friday's Child")
This starship was only mentioned in dialogue.
The name of this vessel was originally the "UES Deirdre" in the first draft of the script (dated 20 April 1967). While "Deirdre" was the generally accepted spelling for this name, the alternate spelling in the form used here was adopted from the revised final draft of the script (dated 11 May 1967), as well as all subsequent reference guides on the subject.