Putting your valuable links that you want followed and indexed in posts or at email list archives: if they use rel=nofollow for http, use the http prefix or no http prefix?
I've been wondering how SE bots treat links that are from email lists that are archived online, and also any links that are at forums. Many places will use the rel=nofollow tag, but will not use it if the link does not have the http prefix.
At an email list of mine, members' posts are archived, and I noticed that when you put in an email (that's quickly archived) a link with the http:// prefix, it's nofollow'd with <a rel="nofollow" (and note that is two spaces between the "a" and "ref", FWIW. Could be just a site-wide coding error FAIK). The links are also real clickable hyperlinks as seen on the webpages. If you put a link in the email as www.whatever.com lacking the http prefix, no rel=nofollow tag is used. The links are also not clickable hyperlinks.
Similar things happen at many forums.
So here's the dilemma and question: which method is best for possibly helping site owners with SERP's? Use www alone, or use the http prefix?
With http the link is not followed, but, the link is clickable, and the link can also show up in SE indexes when searching for the link's URL. So obviously they "see" the link/URL for if they did not it would not show up in any searches for the URL. I've tested that so I know it does, but does that really help?
*What exactly and precisely, techically, is taking place when a bot sees a rel=nofollow link? Do they really not follow the link? Or do they 'follow' it, but will not actually re-index/visit or index that link/URL (if it did not exist anywhere else on the internet)?
On the other hand, without http and just using www alone, the rel=nofollow tags are not automatically generated. And I also know that SE's do see those kinds of links. (**Check your G WMT area for IBL's or for 404's from elsewhere and you may see some of them are NOT clickable http hyperlinks). But if a "link" (URL) is not really a clickable hyperlink, do the SE bots actually follow those?
**More: I've found some IBL's to invalid pages, site owners using the wrong URL, and when I go to the page (if I can find it), sometimes it will NOT be an actual clickable hyperlink, they either will only use www alone, or, they will not use the href hyperlink code, only having on the page the raw text http://www.whatever.com or www.whatever.com.
So in light of that, I would tend to think just using www alone would be the preferred method. Unless (*) bots may actually still be following in that (*) case described above.