# PDFs or PDF's **URL:** \ **Category:** Factual Questions\ **Created:** [March 5, 2012, 8:22pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853 "2012-03-05T20:22:03Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![ClarenceClancy](https://avatars.discourse-cdn.com/v4/letter/c/df788c/32.png) [@ClarenceClancy](https://boards.straightdope.com/u/ClarenceClancy)\ **Post date:** [March 5, 2012, 8:22pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/1 "2012-03-05T20:22:03Z")
What is the official general rule for this? PDF’s or PDFs? ---
**Author:** ![Acsenray](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/acsenray/32/4519_2.png) [@Acsenray](https://boards.straightdope.com/u/Acsenray)\ **Post date:** [March 5, 2012, 8:23pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/2 "2012-03-05T20:23:54Z")
What do you mean by “official”? This is a question of style. You consult the style guide used for your publication. If you are not writing for a publication, you can decide your own style. Personally, I prefer “PDFs.” ---
**Author:** ![Jas09](https://avatars.discourse-cdn.com/v4/letter/j/d07c76/32.png) [@Jas09](https://boards.straightdope.com/u/Jas09)\ **Post date:** [March 5, 2012, 8:24pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/3 "2012-03-05T20:24:24Z")
> **[Acronym | Representing plurals and possessives](https://en.wikipedia.org/wiki/Acronym_and_initialism#Representing_plurals_and_possessives)** > > There is a question about how to pluralize acronyms. Often a writer will add an 's' following an apostrophe, as in "PC's". However, Kate Turabian, writing about style in academic writings, allows for an apostrophe to form plural acronyms "only when an abbreviation contains internal periods or both capital and lowercase letters". Turabian would therefore prefer "DVDs" and "URLs" and "Ph.D.'s". The Modern Language Association and American Psychological Association prohibit apostroph Possessive plur... Chicago says only with a period or both capital and lower-case letters. MLA says no. APA says no. ---
**Author:** ![Blakeyrat](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Blakeyrat](https://boards.straightdope.com/u/Blakeyrat)\ **Post date:** [March 5, 2012, 8:29pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/4 "2012-03-05T20:29:06Z")
> [@ClarenceClancy](#): > > What is the official general rule for this? PDF’s or PDFs? I’m going to take a third option and say: PDF files. ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [March 5, 2012, 10:04pm UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/5 "2012-03-05T22:04:48Z")
I guess you missed [the big fight about this raging in another thread](http://boards.straightdope.com/sdmb/showthread.php?t=643448). 😃 ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [March 6, 2012, 12:12am UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/6 "2012-03-06T00:12:06Z")
In general, omit punctuation if it doesn’t serve a purpose. The apostrophe in “PDF’s” doesn’t serve a purpose (eg making pronunciation clearer, as in “A’s and E’s” versus “As and Es”), so I’d always leave it out. Edit: unless, of course, the context is “the PDF’s properties” or “the PDF’s on its way”, or something. 🙂 ---
**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\ **Post date:** [March 6, 2012, 1:21am UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/7 "2012-03-06T01:21:17Z")
In general, the apostrophe for plurals is being phased out. It only remains when the lack of it would cause confusion (e.g., “A’s” vs “As”). ---
**Author:** ![ChickenLegs](https://avatars.discourse-cdn.com/v4/letter/c/ecc23a/32.png) [@ChickenLegs](https://boards.straightdope.com/u/ChickenLegs)\ **Post date:** [March 6, 2012, 2:51am UTC](https://boards.straightdope.com/t/pdfs-or-pdfs/614853/8 "2012-03-06T02:51:08Z")
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