<meta name="robots" content="noindex" />
Now it just changed to the above, and Google has this thread index, whereupon it wasn't there a few minutes ago, as I have shown and everyone here would have experienced the same thing I did at the time.
Allegedly its prevent search engines indexing duplicate content, which is very bad for SEO.
Also from briefly reading a couple threads over @ the SMF forum on the issue, in this version of SMF, the search de-duplication doesn't work well.
I just noticed when I referenced a different thread from my watchlist (i.e. goto "new" posts) the noindex directive is given. This would support the theory that SMF sets it on "special" pages to avoid duplicate content for crawlers.
When I open the same thread directly from the main forum list, noindex is not in the source.
/end side-track.
Apologies for derailing this thread, for that wasn't my intent. I am though wondering if there's a direct correlation between the content of this thread and what's being released into the wild, hence this micro crusade.