Abbreviations in Archive Reference

Unfortunately, your link goes to a general page without any of the abbreviations.

Fol = folio OED

A. n. With reference to pagination.: 1. A leaf of paper, parchment, etc. (either loose as one of a series, or in a bound volume) which is numbered only on the front.In the early instances the word may have been regarded as Latin. The front and back of the leaf were referred to as (folio) recto and verso; these words became English as nouns

1533 T. More Debellacyon Salem & Bizance i. xiiii. f. lxxxiv The .xlv. chapyter of myne apologye begynnyng, fo. 243.

1669 S. Sturmy Mariners Mag. ii. xvii. (margin) Place this between folio 202. and folio 203.

Note the italicised bold above 16v = 16 verso. 17r = 17 recto.