Good punctuation, that is. But it would seem that there are still a great many people who have no idea how to go beyond the basics.
One of the most successful non-fiction books of recent years was Lynne Truss's Eats, Shoots and Leaves. But while this rode high among the bestsellers for weeks (and was a most entertaining read), I have a feeling that she was probably preaching to the converted, for incorrect use of puntuation seems to be on the increase.
My favourite punctuation mark has to be the much-neglected semi-colon. That delicate little pause, not quite a full stop, can lend elegance to writing. But I doubt whether most schoolchildren have even heard of it.
And my least favourite? Oh, it has to be the exclamation mark; worse even than the ubiquitous apostrophe. The exclamation mark is beginning to lose all its meaning; it is used for stress, to emphasise a "joke" (thus removing any humour that might have remained), and in twos and threes for...what? "We went to the beach!" "And brought a picnic!!" (So?)
Christmas round robins are full of exclamation marks. In some, every holiday, achievement, house move etc. is accompanied by an exclamation mark. Why? I have no idea. I can understand why someone's less than brilliant offspring achieving an A in physics might deserve an exclamation mark (suprise!), but otherwise, please leave it out. And (to pre-empt complaints), if I place an exclamation mark after the acknowledgement of a comment on a post, it's because it really is an exclamation, or to show that I'm not taking myself too seriously! (You see?)