The punctuation marks are all segmental units of writing — i.e. they fully occupy a position in the linear sequence of written symbols. There are, however, various non-segmental features which can serve the same kind of purpose as the punctuation marks. For example, titles of literary or other works may be italicised as an alternative to being enclosed in quotation marks.
In virtually all written material the apostrophe is physically — or, as we shall say, graphically — identical with a single quotation mark. We need, therefore, to distinguish between two kinds of concept which we will call indicators and characters. The characters are the graphical shapes, or symbols, that realise the indicators. Apostrophe and single quotation mark are then distinct indicators that may be realised by the same character.
At the first level we can distinguish three uses of the (ordinary) hyphen:i. To join grammatical components in complex words: the hard hyphen
ii. To mark a break within a word at the end of a line: the soft hyphen
iii. To represent in direct speech either stuttering ('When c-c-can I come?') or exaggeratedly slow and careful pronunciation ('Speak c-l-e-a-r-l-y!')
The terms 'hard' and 'soft' are taken from word-processing: a hard hyphen is introduced into a document by a keystroke, while a soft one is inserted by the word-processing program.
This is used instead of an ordinary syntactic hyphen with adjuncts consisting of nouns or proper names where the semantic relation is "between X and Y" or "from X to Y":
It can be used with more than two components, as in the London–Paris–Bonn axis. It is also found with adjectives derived from proper names: French–German relations. There is potentially a semantic contrast between the two hyphens, as in the Llewelyn–Jones Company (a partnership) vs the Llewelyn-Jones Company (with a single compound proper name). This hyphen is also used in giving spans of page numbers, dates or the like: pages 23–64, Franz Schubert (1797–1828).
iii. separation: A's PhD's if's 1960's
A minor use of the apostrophe is to separate the plural suffix from the base, as in [7iii]; this occurs when the base consists of a letter (She got three A's in philosophy), certain kinds of abbreviation, a word used metalinguistically, or a numeral.
fyi but you probly know this: the special-assignment plural apostrophe-S is called standard by the Oxford Companion to the English Language.
I'm woefully short of dead tree reference materials, but I'm not too surprised.
It seems like at least some version of this apostrophe should be standard for everyone, and that the people who get upset by it wouldn't if they would just stop and think about it...