Robert_Charlton - 8:09 am on Mar 17, 2012 (gmt 0)

In the olde days, when some people believed that text in comments might have an effect, I ran several tests looking for commented-out unique text strings, just to clear up any argument... and I've never found any evidence that Google indexes such text. Never.

There is a way, though, I can imagine that text in comments might perhaps cause difficulty, even though Google doesn't index such text....

In public site reviews over the years, I've seen Matt Cutts make wisecracks about spammy comment tags he came across, and I can imagine that if you had a page filled with a bunch of such comments... I mean really stuffed... and the Google spam team did a manual check of your site and found it otherwise questionable, the stuffed comment tags might suggest to a human reviewer that your intentions were manipulative. Google is big on intent, and it's conceivable that spammy but ineffective comment tags might tip the balance of a close opinion against you. Unlikely to happen, but conceivable.

Usually refers to product specification changes so that we can track them.

No reason whatsoever you should be concerned about these.