Decommissioning was the act of taking a ship, device, or computer program out of service. A starship that was decommissioned could be said to be put in mothballs. Decommissioned vessels were often stored at surplus depots.
In 2285, the USS Enterprise was due to be decommissioned due to age and battle damage, although the vessel was ultimately hijacked by Admiral James T. Kirk. Kirk later self-destructed the vessel over Genesis to kill a Klingon boarding party. (Star Trek III: The Search for Spock)
Following the Khitomer Conference in 2293, which formalized peaceful relations between the Federation and the Klingon Empire, Starfleet ordered the USS Enterprise-A to return to Spacedock for decomissioning. (Star Trek VI: The Undiscovered Country)
The starship T'Pau was decommissioned in 2364, and was later sent to Surplus Depot Z15 at Qualor II, where it was registered on stardate 41334.2, and stationed at Section-18-Gamma-12. At that time, it was stripped of materials, armaments and sensors, its navigational deflector array being routed to the holding vessel USS Tripoli. During this, a file was created for this ship and stored in the Qualor II Depot Z15 Inventory Database. By 2368, other decommissioned starships at Z15 included the USS Alka-Selsior, B-24-CLN, two Miranda-class starships, and a K't'inga-class cruiser. (TNG: "Unification I", "Unification II")
The lateral vector transporter was considered obsolete by both Starfleet and the Vulcans by 2249, and had been largely phased out by that year. Some ships, such as the USS Shenzhou and USS Hiawatha, continued to use them regardless. (DIS: "Battle at the Binary Stars", "Brother")