[ntp:questions] poll interval - RFC compliance question

David Woolley david at ex.djwhome.demon.co.uk.invalid
Sat Jun 14 20:34:18 UTC 2008

David L. Mills wrote:

> statement in the distribution. Note very carefully that there is no 
> license, only a copyright statement that clearly specifies no fee, no 

If that were really true (that there was no licence), almost no-one 
would be able to use the code.  A copyright notice says what is 
copyright and who owns the copyright.  It just removes doubt as to 
whether a licence is needed (not much software was written by people who 
have been dead for 70 years, so most software needs a licence; software 
written by the US government, at least within the USA, is a special 
case), and tells you who is able to give that licence.

A licence is a statement of permission to do things which would 
otherwise be illegal.  Copying the ntpd code would be illegal without a 

> restictions on use other than including the copyright statement itself 
> in derived products.

The statement that there are no restrictions is actually the licence.

You may be confused by commercial software, which doesn't use a bare 
licence, but uses a licence agreement, which is actually a contract. 
Note that some people argue that bare licences are not possible in many 
countries.  Some people even argue that bare licences are not valid in 
the USA.

To the extent that copyright agreements are optional, their purpose is 
normally to give you a copy only on the condition that you do not 
exercise some of the rights that you would have if given the copy 
without making the agreement.

I suspect Open BSD's problem is that the statement of permission doesn't 
actually give all the rights that are restricted by copyright.  In 
particular, if it says "use", that has a technical meaning that doesn't 
include copying to give to others.

People in the ntpd community generally assume that the copyright owners 
will act as though the licence you intended exists, but others may want 
to act on the basis of what the licence actually says.

Normally the following would be taken as implied, but I will make them 
explicit, as an example.  I'm not a lawyer, so they may well not be 
watertight.  You should independently verify any statements about the 
law made here.

Copyright notice:  This article is Copyright 2008 David J Woolley of 
London England.
Parts prefixed ">" are Copyright 2008 Doctor David L Mills and/or the 
University of Delaware (and are included under the doctrine of fair use 
for criticism or review).

Licence:  David J Woolley grants permission for all acts covered by 
copyright law which contributors to a USENET newsroup gatewayed to a 
public mailing list would normally expect to be permitted.

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