6591c9e4_rel_values___Microformats_Wiki___specification_where_possible_
[Keyword] nofollow [Effect on link] not allowed [Effect on a, area] external relation rel-nofollow
indicates that the destination of that hyperlink SHOULD NOT be afforded any additional weight or ranking by user agents which perform link analysis upon web pages (e.g. search engines).
existing rel values · Microformats Wiki
Brief description (from the relevant specification where possible)