Is the use of pp. as in pp. 54-56, meaning pages 54 to 56, used due to a certain meaning of “pp.” or is it just a contrivance?
I’m not certain, (WAG, in other words,) but I always thought it was ‘p’ for page, along with the now old-fashioned convention of doubling up an abbreviation in order to indicate the plural form.
For many abbreviations, reduplication of a letter indicates pluralization. “p. 12” is customary shorthand for “page 12,” and “pp. 12-15” for “pages 12 through 15.” Likewise, “ms.” is “manuscript” and “mss” “manuscripts.” There’s some argument about the meaning of “cc:” whether it’s “carbon copy/-ies” or marking a plural number of copies, but the customary usage for “blind copy” (i.e., “other recipients don’t know he got a copy of this”) is “bc:” for one person sent a blind copy and “bcc:” for multiple recipients of blind copies.
Likewise, “p. 12f” indicates material on page 12 continuing on, presumably, page 13, the implication being that relevant material follows shortly but is separated by irrelevant stuff. But “p. 12ff” means “a bunch of relevant material found in dispersed areas on page 12 and several pages following shortly thereon.”
The typographic symbols for section and paragraph, resembling a spiral galaxy and a mirror-image P with double uprights respectively, are also doubled to indicate plural sections or paragraphs.
According to the **Century Cyclopedia and Dictionary ** your WAG is correct.
pp. is pages as the plural of p. being the abbreviation for page.
Jim
Yep, repeating the letter indicates a plural; as an example, in spanish U.S. is abreviated EE.UU (“Estados Unidos”).
Thanks all. Seems overally formal, as the symbols “p. 35-55” already make it clear that you are referring to multiple pages. No? 
Also, I thought p. 25f meant “see the foot notes on page 25.” I guess that is wrong?
It is, and with some, perhaps many, publications the style is to write it exactly as you’ve indicated, with just a single “p.” My preference is definitely towards this form.
On a related note, can someone tell me where the abbreviations “pg.” and “pgs.” come from? My students seem to prefer these to the clearer and more elegant “p.” and “pp.” I can’t figure out why (and mentally, I picture numbered pigs every time). They also seem to like “ln.” for “l.” [=line]. I’m sure there’s a style guide out there that recommends pg., and that I’m wrong for writing “ABOMINATION: USE P. INSTEAD” in big red letters.
Well, “pg” is in the Random House Unabridged Dictionary and American Heritage Dictionary, but I can’t think of a stylebook off-hand that recommends its usage.
I see it used all the time. It seems a natural abbreviation to me; much more so than pp. (You really shouldn’t call stylistic differences abominations, jeez; I mean writing in all-caps and using red ink strikes me as much more abominal.")
Don’t worry, that part was a joke.
Consult The Abominable Style Guide to English Usage, or, You Ain’t Seen Nothin’, Yeti by C.P. Snowman. 
YOU HAVE A PROBLEM WITH THAT?, HUH!?
LOL!!!
I heard that didn’t sell well at all. Almost destroyed Snowman’s career and sent him over the edge. He was very lucky, though. After all, bumbles bounce.