By the way, I notice that my post count is stuck at 66. Is this a hint?..
Isn’t “Mens’s” usually associated with that other gender?
No foolling now. It’s John’s car.
There is no exception.
I’m gonna guess here and say the t-shirt was (at least) printed in a non-English speaking country. I’d guess China, but it could be from nearly anywhere.
Of course it could be a simple typo that wasn’t caught, but I blame furriners.
-Rue.
Pervert.
Yeah, like I’m gonna take language tips from someone who misspells “fooling”. 
It’s not my fault. It’s this stupid message board software. It won’t let me use word, and I can’t proofread.
But trust on me on this, It really “John’s car.” A generally good rule of thumb is that our grammar makes no exceptions to avoid confusion or for any logical reason. All exceptions will be arbitrary.
That’s my experience too. It’s generally a fairly easy language, yet I always find it amusing to learn something new.
So thanks. 
Your welcome’s.
John’s car? I thought it was my car!
StG
Here are some people who can’t choose between “pros” and “pro’s”
Both “Good People to talk with… Love Pro’s!” and “Love Pros (Therapists) can guide you …” on the same page. Of course, neither of them is as funny as this gem:
“Educated answers” with abominable spelling and grammar. Nice.
Hey, Scylla called me a pervert! That’s got to be good for something.
Also, I just realized that “mens’s” resembles a contraction, and contractions are associated with the same organ of that other gender’s that is largely responsible for “mens’s.” How deep does this rabbit-hole go?
No “exception to the rule” here – it falls under a different rule. Possessive pronouns – my/mine, your/yours, his, her/hers, its, our/ours, their/theirs – are their own category, no apostrophe involved.
To help clarify the issue with men’s department:
plurals (note that none end in s): men, women, children, people
plural possessives: men’s, women’s, children’s, people’s
Old joke: “Don’t you know the Queen’s English?” “Yes, I was aware of that”
I’ve opened up a can of worm’s.
Double grrrrrrrrrrrrrrr.
mens’s ??? good grief, if I ever saw that sign on a restroom door I would run screaming from the building… men’s is correct, although I could live with mens’ (at least, if i was desperate for the loo) mens causes my mind to boggle (how can you have more than one ‘men’ - it would be like having two ‘everythings’) but again, probably wouldn’t prevent me from using the facilities… but mens’s… ugh, I can barely even type it…
I hope you don’t run like the prose in Scylla’s* post.
- [sub]Scylla is[/sub]
How about “his shirt”, “her pants”, or “their clothes”?
Did you consider that the monitor might have been shipped in an old box, formerly containing other items?