The MK 23 MOD 0 was built as an "offensive" handgun for U.S. special operations forces under USSOCOM, as per request made in 1989. Military versions of the firearm have the writing "MK23 USSOCOM" engraved on the slide. The first MK 23 production models were delivered to SOCOM on May 1, 1996. The first use of MK23 USSOCOM handguns of which I'm aware was by the US Military Advisory team in El Salvador circa 1987-1990, who were restricted by congress from carrying rifles but could carry handguns. Both the MK23 and H&K SP89 handguns were fortunate results of that limitation.
I'm talking about the new 'Mk 24 Mod 0' pistol that replaced it.