Apostrophe not allowed in Carry-ons

This sign posted at SeaTac has an errant apostrophe which does not appear on similar documents on the TSA 3-1-1 website, nor on those posted at the airport in San Jose.

How one's small mistake cost M&S a small fortune

From This is London:

With its cute message, Marks and Spencer's sleepsuit was just the thing for a new baby's first Christmas.

There was only one problem - that bane of grammar-aware shoppers, an unnecessary apostrophe.

The suits have emblazoned across the chest the phrase "Mum's dreaming of a quiet Christmas just like the one's she used to know".

Oh boy... the possessive of "y'all" is "y'all's"?

A little southern-style grammar for y'all this morning:

"Y'all," being authentically Southern, does things differently. It adds an apostrophe and "s," as though "y'all" were a noun. So the proper possessive of "y'all" is "Y'all's." The first apostrophe signals the omission of the letters "o" and "u" in "you all." The second signals the possessive case.

(Link)