What is "disclaiming" a copyright ?

[Charles Plessy <charles-debian-nospam@plessy.org>]

Deat all,

I have almost finished to prepare a debian package for dialign (a
multiple alignment software), and I have a question for the english
native speakers of this list:

What is the meaning of the following ?

" Burkhard Morgenstern hereby disclaims all copyright interest in
    DIALIGN, written by Burkhard Morgenstern and Said Abdeddaim."


I suspect that one of the copyright owners gives its rights to the other
one, but which one ?

Best regards,

PS : I have uploaded the package on mentors.debian.org.

-- 
Charles Plessy
Wako, Saitama, Japan