"notranslate"
http://googlewebmastercentral.blogspot.com/2008/10/helping-you-break-language-barrier.html

"robots-nocontent"
http://help.yahoo.com/l/us/yahoo/search/webcrawler/slurp-14.html

"maps_off"
http://www.mapmypage.com/

"vcard"
http://microformats.org/wiki/hcard

Microformats related Class Names, many!
http://microformats.org/wiki/class-names

// special classnames associated with libraries:
class="sortable"
class="nosort"
class="reflect"
class="unsortable"
class="instant"
class="reflex"

plone: http://plone.org/products/plone/releases/2.1.3
class="tile"

popular classnames:
http://code.google.com/webstats/2005-12/classes.html
class="footer"
class="menu"
class="title"
class="small"
class="text"
class="content"
class="header"
class="nav"
class="copyright"
class="button"
class="main"
class="search"
class="msonormal"
class="date"
class="smalltext"
class="body"
class="style1"
class="top"
class="white"
class="link"


rel tags! nofollow etc are another issue.