I think the Ranger has had AC standard for 20 years.
AC was still an option on XL trim at least as late as 2001 in some states. A member here, Citoriplus, owned the nearly identical (when stock) twin of my 2001 Ranger, but I don't think his truck had AC.
The XLT package is just nicer standard trim. The content differences between the XL and XLT vary from year to year.
From 1993-2000 the XLT package added chrome bumpers, a chrome grille, carpet, and nicer door panels. A cassette player and cloth split bench were standard on the XLT, but optional on the XL. Also, in 1993-1994 some XLs actually came with carpet.
There was an XL only Sport package in 1993-1994 that included XLT style aluminum wheels and decals similar to those on STXs. Later on the Sport package became available for both the XL and XLT. The later Sport package included painted bumpers, a painted grille, and 15x7 wheels.
In 2001-2002, the XLT package included all of the previous upgrades, plus 15x7 wheels, upgraded side mirrors, and a CD player. In 2003 chrome was no longer standard and was optional in an "Appearance Package." Around 2004 or 2005, Ford added a "Value Package" for the XLT that deleted the carpet. XLT trim has varied since then, but the basic idea is the same.
Keep in mind, packages can vary by region. My truck's group of options are part of a regional package. It was sold new in NC.
Apparently the package applied to trucks ordered with the Appearance Package or Flareside bed...my truck is not a Flareside.