Elephant logo in a book

Hello,

i got a somewhat curious request on de(at)postgresql(dot)porg:

For a book with the name "Markentiere/Corporate Animals" they want to
use (among others) the PostgreSQL elephant logo. What is the license for
the logo and can it be included in the book?

They also want me to sign a license contract - but I will reject this
request.

The publisher is german, the name is "Die Gestalten". The website is:

http://www.gestalten.com/books

Source of the logo:

http://www.brandsoftheworld.com/search/logo/postgresql

Although I think, the regular logo from the pgfoundry website should be ok.

Opinions?

--
Andreas 'ads' Scherbaum
German PostgreSQL User Group
European PostgreSQL User Group - Board of Directors
Volunteer Regional Contact, Germany - PostgreSQL Project