The Territorial Forces began with a variety of names and purposes, but standardized into the Regional Forces and Popular Forces, grouped as RF/PF or "Ruff-Puffs." These were separate from the regular Army until 1970. Regional Forces were organized into companies, controlled by province chiefs, and Popular Forces organized as platoons, controlled by district or village chiefs. In Jun 1965, there were 969 authorized RF companies and 3892 authorized PF platoons. The RF also included some armored car platoons, boat companies, and other odds and ends.
By the end of 1965 RF strength was about 130,000 men; this nearly matched their authorized strength, and an increase of 20,000 personnel for the 1966-67 period was authorized. The PF, however, had only 135,000 of their authorized 185,000. Despite this, MACV approved an increase to 200,000 personnel for 1966. For the RF, the 1966-67 plans became an increase from 767 to 888 companies and about 135,000 personnel to 155,000. Note that the number of companies active and planned were both well below the number that had been authorized in Jun 1965. At least 40 of the new RF companies were to come from the Special Forces-led CIDG. Other manpower problems led to a freeze during 1966 to a planned RF strength of just under 142,000 in 1966 and 152,500 in FY 1967. The PF were to aim for a total of 176,200 in 1966 and 147,400 in FY 1967.
By Oct 1967 the RF had 896 companies, 24 riverine companies (eight landing boats each, all located in the Delta area), and a platoon of 6 armored cars and a logistics company in each province. The PF had 242 intelligence squads (one per district) and 4121 platoons. Some of these were new units, since 99 RF companies and 446 PF platoons were activated in the period Jul – Dec 1967.
In Mar 1968, MACV proposed grouping the RF companies into battalions, with a plan to activate 177 battalion headquarters. In 1972, the authorized strength of the RF was 300,600 and of the PF 227,900.
In 1974, the Army began to convert sector headquarters to mobile group commands, with two-four RF battalions and a four-gun battery. The plan (obviously never completed) was to form 27 such groups by Jun 1975.