Good Grief!

Was I right to be distraught over my plural possessive gaffe? MLA (Modern Language Association) says I’m wrong to say Rees’ comics instead of Rees’s comics. But what about other style manuals?

• Chicago Manual of Style: according to the website FAQ, I’ve got some leeway here:
  

  Q. When indicating possession of a word that ends in s, is it correct to repeat the s after using an apostrophe? For example, which is correct: “Dickens’ novel” or “Dickens’s novel”?

  A. Either is correct, though CMS 15 recommends the latter. Please consult 7.18–22 for a full discussion of the rules for forming the possessive of proper nouns, including exceptions and examples. For a simpler statement of the rule, see paragraph 5.26. For a discussion of the alternative practice of simply adding an apostrophe to form the possessive of proper nouns ending in s, see paragraph 7.23.

• Strunk and White’s Elements of Style:
  

  Form the possessive singular of nouns with ’s. Follow this rule whatever the final consonant. Thus write,
  

  • Charles’s friend
  • Burns’s poems
  • the witch’s malice

  This is the usage of the United States Government Printing Office and of the Oxford University Press.

• Associated Press (AP): I don’t have a copy, but a University of Utah faculty member references the AP possessive rule:
  

  The main AP exception to Strunk and White’s Elements of Style involves forming the possessive of a singular proper noun that ends in “s.” AP says merely add an apostrophe. Examples: Otis’ cookies, Amos’ ice cream, Charles’ chips.

Conclusion? Doesn’t seem like something to lose any sleep over, though I’ll defer to Strunk and White and the MLA in the future.