commas before "too"

[marci]

Is it up to the writer to put a comma before "too," or is there a steadfast rule? I see it both ways in books, and I'm wondering if the rules are a little loose in that regard.

[Bufty]

Google is wonderful.

http://www.absolutewrite.com/forums/showthread.php?t=88239

[Esquart]

From the thread cited:

Without the comma, these indicate to me there's a store called Macy's too.

Ah, but there could be a store called "Macy's, too" too!

[Libbie]

I'm a bit of a comma freak. I always, always put commas before too. Without digging out my Elements of Style, I'm fairly certain that the comma before too is considered correct, but dropping it is becoming one of those stylistic things that are optional. Not strictly correct, but acceptable.

[missteddy16]

I learned punctuation off of transcribing "Harry Potter." Rowling puts a comma before too.