Niiiice! Very nice! Thanks for that little lot. Your response sent me doing a bit of surfing; found this site:

http://grammar.about.com/od/terms/f/whatisaghostword.htm

and was about to refer you to this one anyway:

http://en.wikipedia.org/wiki/Ghost_word

I may find myself moved to augment the latter in the light of your contribution.

Cheers,

Jon