If i have a page ("dontFollowMe.html") with the meta tag:
< meta name = "robots" content = "noindex, nofollow" / >
... and I link to that page ...
Do I need to include the nofollow rel attribute to the a element? :
<a href="dontFollowMe.html" rel="nofollow">sign in</a>
Best How To :
No, you don't necessarily need to use nofollow on a page that is noindexed (for technical reasons, as your question described).
nofollow = "Do not pass link juice to this page. Just pretend it doesn't exist". Of course, this is just a suggestion to the search engines.
noindex = "Do not index this page. I don't care whether other pages linked to it as followable or not, just don't index it."
For SEO reasons: if this question is assuming you're linking to an internal page, then the answer to your question would be that typically you would want to nofollow the link to this unimportant page and also noindex it on the unimportant page.