xxx is a trademark of yyy

[Brad Templeton]

You do not need to worry about "Guru" being a trademark, in particular
because it is a normal word.

Trademark law is very tricky, but as I understand it, a trademark has to
be an adjective, and can never be a noun.
This means that there is no such thing as "Unix".  There is the "Unix operating
system", where the word is an adjective.  Companies wanting to keep their TMs make
sure they refer to things like "Frisbee BRAND discs" and never "Frisbees",
because there is no such thing as a frisbee.

The reason for this distinction is clear.  When you trademark something,
you claim use of the adjective as it refers to a certain noun or
class of nouns.  Nothing stops me from bringing out "Apple" brand hand-soap
even though there is a registered trademark for Apple brand computers.
If a word is invented like UNIX, I am not sure of the rules.
Some day it might be possible to come out with Unix brand soda-pop.
("Nothing goes down easier than Unix Soda") but I am not sure of that now.
-- 
	Brad Templeton - Waterloo, Ont. (519) 886-7304