Re: Updating copyright years

["Stephen J. Turnbull" <stephen@xemacs.org>]

Carsten Mattner writes:
 > Ted Zlatanov writes:

 > > Doesn't the act of modifying the file to insert the new year make
 > > the file modified and thus require the new year?  Heh heh.

No.  Dates are not expressive works.  Q.E.D.

 > Does anyone know why it's required to include a date (year) in
 > copyright headers.

I don't know what the current situation is exactly, but the basic
thing is that in the U.S., the automatic Berne Convention copyright
doesn't require any notice at all (of course that's true of all Berne
Convention signatories).  If you receive a work with no notice, you
must assume that all (copy) rights are reserved to the owner, even if
you don't know who that is.  However, the owner's powers of
enforcement are basically limited to a cease-and-desist order on
copying, and destruction of existing unlicensed copies.

If you want to press criminal charges, and IIRC also to sue for
damages (at least for statutory damages), you need to register your
copyright, and in turn you are obliged to provide a notice of
copyright, including when copyrights in the work were established.
The reason for that requirement today is mostly moot: copyrights do
expire (although we'll probably not see that day), and the copyright
notice tells the user when.

 > In the same context, do all licenses lend themselve to just be
 > referred in the file
 > header (foobar $LICENSE_NAME .... found in LICENSE), or is this dangerous?
 > Is a complete verbatim copy of the license a requirement? Maybe if
 > the file is distributed separately?

The problem with a permission-by-reference is that the user doesn't
know what her rights are, not that the owner of the copyright can't
enforce any restrictions that they choose to maintain (if they're
enforceable at all, of course).  With a well-known license such as the
GPL, it's really not necessary to provide a copy of the license from a
legal point of view (except in cases where it's an invariant section
in an FDL document or the like).  However, the GPL is also an advocacy
document, so providing it in every distribution is a GoodThang.