Abbreviations are not Contractions, and Plurals don't need Apostrophes

I finally figured it out!!  Sort of.

When people sell CD's -- they put an apostrophe because the abbreviation for compact disc is CD.

But -- repeat after me -- an abbreviation is NOT a contraction!

Other plurals with apostrophes are just silly. When I see a street vendor's sign announcing that fruit's, vegetable's, and CD's are being sold, I cringe.
(the vendor owns the sign, but the fruits, vegetables, and CDs are plural, not possessive)

CD's is wrong, but at least there is some logic behind the mistake.

And perhaps when people realize where that mistaken logic comes from -- when they realize they are mistaking abbreviations for contractions -- perhaps they can start to change.

I used to think that we used an apostrophe in it's when we meant "it owns something." Perhaps at one time we did (we used to put two spaces after a period in sentences, after all). Perhaps it was an 80s trend. It feels like an 80s trend. Maybe it was something we (I would say I am alone in my mistake, but have you read Facebook posts lately? I have learned, adapted if need be, and now I'm waiting on others to catch up.) mis-learned in second grade when we saw all those other contractions with apostrophes -- he's, she'd, you'll, they've. But those work because contractions include a noun and a verb. It's (meaning IT IS) is still written that way.

Click picture to purchase -- it is not owned by me and I don't get paid for you to click it, just FYI.

When we write ITS like in the example of the dog losing its collar , we forget that it's (it is -- see what I did there?) the same kind of word as his and her -- which also don't have apostrophes -- not he is, and definitely not HER IS. (I shivered a little writing that, not going to lie.)

Still, ambiguity exists.
Mothers Day or Mother's Day or Mothers' Day
all the holidays can be punctuated or not and it's acceptable.

Shortened expressions like
thank yous or thank you's
either are accepted based on meaning, and often both are accepted forms.

Names written on family signs, like The Campbell's instead of The Campbells
are also ambiguous without the context of the rest of the sentence.

Writing letters as letters, like minding your Ps and Qs or dotting your i's versus crossing your t's, can be written both these ways so long as the writer sticks with one through the entire document.

So shortened expressions SHOULD follow the same rule we now accept for CDs. We should remind our children to say their thank yous as we leave their grandparents' house.
However, because thank yous often refers to written thank you notes, thank you's with the apostrophe seems to replace the missing word notes, and most of us are overall fine with that.

Names can indicate possession when the family collectively owns something.
The Campbell's house is brown.
The Campbell's dog is non-existent.
The Campbell's house or mailbox

But the name does not show ownership in the following examples:
The Campbells (more than one of them) are coming.
We are having the Campbells over for dinner.
The blue house on the corner belongs to the Campbells.

The overall take-away from this lesson is -- if in doubt, leave it out!  That is especially true for apostrophes.

On that note:

Happy Mothers Day to all the mothers and all who mother!