I notice an increasing appearance of elisive apostrophes in printed English, particularly can't, or won't. In my schooldays I was taught that this was entirely incorrect except in reported speech.
The house style of the publication I currently work for is to
always use elided forms, the idea being to keep the tone informal, friendly and reflecting the way people talk. The house style of the last publication I worked for was to
never use elided forms.
Personally, I think any rule that says "always" or "never" is silly - you need to judge each case on its merits, otherwise you can end up with sentences that sound very unnatural and clunky. And some elisions are really
ugly (eg "should've" or "would've").
Fortunately, as chief sub on my current publication, I get to enforce the rules as I see fit (though most of our style rules predate me and are firmly entrenched, so I can't get away with making major changes), so while I tolerate most elisions, the rule for me is not a blanket "always do this" or "never do that" but to make sure that the flow and rhythm of a sentence is natural and doesn't make the reader stop to think about it.
d.