ABBR vs. ACRONYM

[mdinowit]

I'm reworking pages on my site to wrap all abbreviations such as SEO, FAQU, etc. in ABBR or ACRONYM tags. The question is, which to use. The criteria does not seem very clear.
One source suggests that an ABBR is for non-spoken abbreviations while ACRONYM is for spoken ones. The example give is lbs. as an abbreviated form of pounds and NATO as an acronym for North Atlantic Treaty Organisation.
So what is SEO? Is it spoken or not? Which would it go under for best result?

Yes, it seems like a silly differentiation and one that should have 0 SEO effect, but I've seen more ranking increase from good editorial and formatting than from just about anything else.

[wige]

SEO is an acronym by definition - abbreviations generally are used shorten an existing word when typing, whereas acronyms are used to create a new "word," spoken or not. The guideline you refer to is more simplistic than that, but I'd list it as an acronym, spoken or not.