Why is this little bit of code showing on my page?

If you look at the very top of the page here:
http://opalessenceshop.com/index.php?main_page=product_reviews&cPath=1&products_id=3

You'll see that before the top of my page starts, it says

[R01.15OZT]" /> [R01.15OZT]">

I can't figure out why. I'm using default templates for the reviews pages...?

Use the Admin - Tools - Developers Tool Kit to search for R01.15OZT to see what file it's in.

Thats one of the part numbers for one of your products. Check your html header file for references pulled for some of your extra meta tags you have added, like the twitter/fb ones

Well I know it's one of my part numbers, silly! I just want to know what it's doing way up there! stevesh: I did that, and it came up with no results.

Well that was weird... it was in my html_header.php, a couple of meta tags... I commented them out to see if the stuff went away, and it did, so I put them back in and the stuff didn't come back! I have no idea why.

See my comment wasn't so silly eh ;)

Well the advice wasn't silly, but telling me that they were model numbers was silly--as if I wouldn't recognize my own model numbers ;)
I still don't know how I fixed it...but I fixed a VCR the same way, oh, 20 years ago. It wasn't working properly, so I took it apart, looked at it, didn't understand a bit of what I was seeing, put it back together, and it worked! Until it got stolen in a home breakin a few years later... :(