Does G consider page formatting a 'site update'?

(minimal text edit like for typos/ clean up html/remove empty font tags/adding alt tags/removing unnecessary tables, etc)
- which changes # lines of code
- also changes file size, some

Or does G really want a discernable change of browser content?

Your search -- "site update" -- did not match any answers in the AdWords Help Center.

http://www.google.com/cse?ctx=en%3Asearchbox&hl=en&cx=003125405486913854919%3A6ixdakj4aiq&from=portal&q=%22site+update%22+inurl%3Ahl%3Den

Can't find the term but, I'd guess a site update would involve any page being updated. Page updates are thought to involve a change in server time stamp as seen in FTP.

Anyone else?

I've heard theories of so many K but they're only that.
Years back.

I've heard theories of so many K but they're only that.
Years back.
Yeah, years ago when Alta Vista was giving a boost to fresh pages I believe. It was thought AV wasn't looking so much at the headers as at the file size.

I'd assume it would still start with the header date: If different, compare versions to find material differences. I'm also going to assume that any changes to overhead that affect how the indexers see the content, even if it remains the same, would have an impact.