80s Or 80’s Or ‘80s For Eighties – Using Apostrophe

I have been seeing incorrect uses of the apostrophe when one uses incomplete numerals for decades. Just a tip for those who aren't sure about this:
Where do I use an apostrophe (’) when I want to talk about decades using incomplete numerals?

When you want to say “Clothes worn in the eighties”, but want to use numerals, this is how it should be:

Clothes worn in the '80s

Clothes worn in the 80's
Clothes worn in the 80s

In this example, the apostrophe is used as a contraction i.e. it replaces something that was removed from its place. Basically, the apostrophe replaces "19" in "1980".