Seeking Grammar Police Ruling - Typo's

[Geoff Bannister]

--- In HPFGU-OTChatter at yahoogroups.com, "Steve" <bboyminn at ...> wrote:
>
> Got into a discussion at Orson Scott Card's Hatrack forums.
> We were discussing a completely different subject and at the
> bottom of my post, I added that I was going to go back and fix
> the "typo's" in my previous post.

<snip>

> Now, without a doubt, 'typos' is the more common usage by a
> wide margin, but it being common doesn't make me wrong.
> 
> Anyone care to weigh in on whether "typo's" is or is not a
> valid contraction of 'typographical errors'? ...Carol?

Geoff:
I would agree partly with Carol that "typo's" would be the
 possessive form of "typo" but it could also be the contracted form 
of '"typo is'". For example: "His typo's completely changing the 
sense of the statement."

No way could it be a plural.