Think of the phrase: about music. “90’s music” would imply music from specifically 90 (probably 1990 where we assume the writer was lazy about the initial apostrophe)—possessive form. “’90s music” uses ’90s as an adjective for the entire decade—and with the preceeding apostrophe makes it clearer 19 is omitted. 1 year versus 10 years as a big difference. Using an apostrophe in the right place clearly removes the ambiguity.

It was an error. It happens, and too many people do it so next time maybe you won’t with a good habit being formed.

for Mobile OS’s

for mobile OSs*

One man’s pedentry is another man’s pet peeve. This is a syntactic error that isn’t just a typo but a misunderstanding of the mechanics of apostrophes.

Hercules’* promise or Hercules’s* promise

The choice is yours.

since I do copy OTP’s

OTPs*

Really. Apostrophes are used for possession & contractions (not making words plural). In this case, you are omitting the 19 from the decade starting at 1990. What is plural is the years inside that decade, meaning the 10s place. All to say, it is 100% ’90s*.

• a lot of pioneering in the ’70s*
• right there in the late ’70s*
• Most people ended the ’70s* living like they did in the ’60s*
• a lot of invention in the ’80s*
• crystalized in the ’80s*
• We emerged from the ’80s*
• lot of evolution in the ’90s*
• a lot of revolution in the 2000s*
• a lot of stagnation in the 2010s*
• Now we arrive in the 2020s*
• In truth this began in the 2010s*
• the sinisterization of the ’20s*

But you got it right for “TRS-80s” & “August of ’91”!

in the late ’90s*

Early ’90s*

You got it right the second time though, champ!

in the ’90s*

in the ’90s*

I think you need to run the service yourself

In the 1980s*

How about Git’s CLI stop being so shit? All of the options are obtuse & usually 3 ways to do the same thing.

Developers should normalize non-Git DVCSs.

’80s*

Ur🐋💦

It’s all too* expensive

Apostrophes are for possession & contractions; plurality isn’t on the list. Soz, m8.

in the early 2000s*

In the mid-’90s*