Is an apostrophe with a decade (e.g. 1920’s) generally considered “incorrect”?

Question

I typically don’t use an apostrophe with plurals in any situation, but I always assumed that the use of an apostrophe in constructions like acronyms:> Forty BA’s were given out to students this year.or numbers:> Though the greatest period instability occurred during the 1950’s when. . . .was more or less ok. I would personally use *BAs* and *1950s* here, but I've never thought the apostrophe in this case was necessarily “incorrect”. What say ye?

Answer 1

An apostrophe is used to show a contraction, so if you are writing:

1990s-- you are not contracting any concepts together. Instead, you are naming a set of years you are discussing.

90's-- This is a contraction because you have dropped the 1900s part of the years. The reader then knows that you mean 1990s. However, a reader can tripped up if you instead mean 1890s, so context is important as it would be with any contraction.