Re: [Editorial] Use of MUST etc (was: comments on SHACL 3 March editors draft)

This sums it up quite well:
https://www.w3.org/2001/01/mp23 <https://www.w3.org/2001/01/mp23>

Some related longer reads:
https://www.w3.org/1999/09/specification <https://www.w3.org/1999/09/specification>
http://ln.hixie.ch/?start=1140242962&count=1 <http://ln.hixie.ch/?start=1140242962&count=1>

Best,
Richard


> On 7 Mar 2016, at 02:39, Holger Knublauch <holger@topquadrant.com> wrote:
> 
> On 7/03/2016 6:59, Peter F. Patel-Schneider wrote:
>> General
>> 
>> There are quite MUSTs in the document that are inappropriately used.  For
>> example, instead of "a SHACL processor MUST use the union of the focus nodes
>> produced by these scopes" say "the scope of a shape is the union of the sets
>> of nodes produced by these scopes".  The place to use MUST is in wording
>> like "a SHACL processor MUST validate a shape against a data graph as
>> described herein".
> 
> Does anyone have a definite explanation under which condition these special terms must be used and when not? I am confused as this distinction feels rather arbitrary to me. I found
> 
>    https://www.ietf.org/rfc/rfc2119.txt
> 
> but that doesn't answer why MUST would be illegal in some cases. I don't see harm in using MUST.
> 
> Thanks,
> Holger
> 
>