By GLEP 76, two forms of copyright notices are allowed for copyrightable
files in Gentoo projects:

A "long form":

    Copyright YEARS MAIN-CONTRIBUTOR [OTHER-CONTRIBUTOR]... [and others]

or a "simplified form":

    Copyright YEARS Gentoo Authors

The latter was introduced because keeping track of ebuild authors is
close to impossible. We didn't want to put any burden on developers to
decide when information about the main contributor should be updated
in the notice. Or, by the GLEP's own wording: "Especially for ebuild
repositories, constantly keeping track of the main copyright holder
of any file would be rather inconvenient and tedious."

Therefore, the recommendation is to use the simplified form (i.e.,
"Gentoo Authors") in the Gentoo repository, at least for ebuilds and
profile files.

Also, when doing a simple version bump based on a previous ebuild, the
existing starting year should be kept. (I am aware that for most ebuilds
1999 will not be correct either. Not sure if aiming for something more
accurate would be worth the effort, though.)

Ulrich