Eats, Shoots and Leaves

They regard us as freaks. When we point out illiterate mistakes we are often aggressively instructed to “get a life” by people who, interestingly, display no evidence of having lives themselves.

But best of all, I think, is the simple advice given by the style book of a national newspaper: that punctuation is “a courtesy designed to help readers to understand a story without stumbling”

Do I have any objection to the construction “a friend of mine” or “a friend of yours”? Well, no. I would never say “a friend of me” or “a friend of you”. And yes, you would say “a cousin of my mother’s”, “a child of hers”. Well, “a friend of the footballer’s” is the same thing! The only time you drop the double possessive is when, instead of being involved with an animate being, you are “a lover of the British Museum”, because obviously the British Museum does not – and never can – love you back.

Current guides to punctuation (including that ultimate authority, Fowler’s Modern English Usage) state that with modern names ending in “s” (including biblical names, and any foreign name with an unpronounced final “s”), the “s” is required after the apostrophe:
Keats’s poems
Philippa Jones’s book
St James’s Square
Alexander Dumas’s The Three Musketeers
With names from the ancient world, it is not:
Archimedes’ screw
Achilles’ heel
If the name ends in an “iz” sound, an exception is made:
Bridges’ score
Moses’ tablets
And an exception is always made for Jesus:
Jesus’ disciples
However, these are matters of style and preference that are definitely not set in stone, and it’s a good idea not to get fixated about them

2 It indicates time or quantity:
In one week’s time
Four yards’ worth
Two weeks’ notice (Warner Brothers, take note)
3 It indicates the omission of figures in dates:
The summer of ’68
4 It indicates the omission of letters:
We can’t go to Jo’burg

When the possessor is plural, but does not end in an “s”, the apostrophe similarly precedes the “s”:
The children’s playground
The women’s movement
But when the possessor is a regular plural, the apostrophe follows the “s”:
The boys’ hats (more than one boy)
The babies’ bibs

Square brackets are most commonly used around the word sic (from the Latin sicut, meaning “just as”), to explain the status of an apparent mistake. Generally, sic means the foregoing mistake (or apparent mistake) was made by the writer/speaker I am quoting; I am but the faithful messenger; in fact I never get anything wrong myself:
She asked for “a packet of Starbust [sic]”.

should remember the fine example of Perekladin, who found catharsis in an exclamation mark, and also of the French 19th-century novelist Victor Hugo, who – when he wanted to know how Les Misérables was selling – reportedly telegraphed his publisher with the simple inquiry “?” and received the expressive reply “!”

our system of punctuation is limited enough already without us dismissing half of it as rubbish.

Unintentional sense from unmarked possessive:
Dicks in tray (try not to think about it)
New members welcome drink (doubtless true)