Physical Composition of the Manuscript
The Voynich MS is a book or codex which is composed of parchment leaves or folios combined, for the most part of the MS, into standard quires. A standard quire (or gathering) consists of four bifolia which are stacked and folded in the middle to form 8 folios. Each quire is sewn into the codex separately, at the combined fold. The size of a Voynich MS bifolium is about 12 inches wide and 9 inches high. It is possible to view the Voynich Manuscript by visiting this web page: http://www.voynichinfo.com/

Foliation
Each folio (of 6 by 9 inches) has two sides. The front is called recto (abbreviated 'r') and the reverse verso (abbreviated 'v'). Each of these sides is what is usually referred to as a 'page'. Thus, a standard quire has 16 pages. The notation to identify a page in the Voynich MS is the character 'f' (for folio) followed by the folio number, followed by 'r' or 'v', so the first quire starts with pages f1r, f1v, f2r, f2v, f3r, etc, and ends with f7v, f8r, f8v. The pages f1r, f1v, f8r and f8v together form one bifolium. The MS used to have at least 116 folios, and the last page of the MS is indeed f116v. This is very helpful, because, if this manuscript was written in an Middle Eastern language that was written right to left, then the back of the manuscript would have been the front. Thus, page 116 would have been the opening page of the book. (This is the page that Dan Gibson has concentrated his tralsation efforts on.)

The Voynich MS once consisted of at least 20 quires, but two of these are now lost. Also, as seen in many medieval codices, a number of quires in the Voynich MS do not consist of the standard 8 folios. What is more unusual is that a relatively large number of bifolia is wider than the standard size. These have additional folds and consequently more than the normal four pages. They are henceforth referred to as foldouts. Many foldouts are bifolia with the width of three pages, but some are even four pages wide. Finally, there is one 18 by 18 inch bifolium which also has a horizontal fold.

Consecutive folio numbers were written onto the MS in the top right hand corner of each right-hand page, with the foldouts folded in. The side of the leaf on which the folio number appears is not necessarily the recto side, due to the various different ways in which the foldouts have been folded in (1). There is one exception to this rule, which is probably due to a change of the fold direction with time.

When all foldouts are completely folded out, to the right of the binding one sees the recto sides of the folios. To the left are the verso sides (of the previous folio). If the folio nr is n, the recto pages are numbered left to right, fnr1, fnr2, etc. On the verso side (with the binding to the right) the verso pages are numbered right to left fnv1, fnv2, ... The exception to this general rule is the pair of folios f85 and f86, which form the above-mentioned multiple-foldout with the horizontal folding crease.

Origin of the current numbering
When the 1931 Petersen photocopy of the Voynich MS was made, all the foldout folios were labeled in white ink on the negative in a hand other than Petersen's (3). These circled page numbers were used in the FSG computer transcription (4). The creases on foldout folios sometimes form boundaries between distinct 'logical pages' and sometimes do not. That is, continuous lines of writing sometimes (but rarely) cross foldout creases.

Quire signatures
Quire markings are written on certain pages. It is not clear when or by whom these were written. They are indicated with an old-fashioned numeral followed by a 9 for Latin -us, and sometimes an 'm' in between (5). Quire markings 16 and 18 are missing, and since there are also missing pages between quires 15 and 17 and between 17 and 19, the reasonable assumption is that these quires consisted of one bifolio each (foldout or not), which have been lost. Furthermore, since the folio numbering also shows gaps over these missing quires, the assumption is that when the folio numbers were written these pages were not missing.