Friendly reminder from BCP 61: Security is a "MUST implement"
<http://tools.ietf.org/html/bcp61#section-7>


On 8/30/11 12:46 PM, Eric Burger wrote:
Can you give an example of where a dangling SHOULD makes sense?  Most often I 
see something like:
        SHOULD implement security
meaning
        SHOULD implement security, unless you do not feel like it or are in an 
authoritarian regime that bans security


On Aug 30, 2011, at 12:11 PM, Keith Moore wrote:

On Aug 30, 2011, at 12:06 PM, Marc Petit-Huguenin wrote:

The meaning of SHOULD is clear for the authors (it "mean[s] that there may exist
valid reasons in particular circumstances to ignore a particular item, but the
full implications must be understood and carefully weighed before choosing a
different course."), the problem is that some implementers use a different
meaning (I do not have to implement this if it is inconvenient or difficult for
me to implement), vendors another one (SHOULD gave us the right to not implement
it).  I even read somewhere, perhaps on this list, about a vendor that rejected
any bug report against a SHOULD.  Conditional MUST, in my opinion, does not have
this problem.

But conditional MUST has other problems, namely that you have to enumerate the 
exceptions for the MUST, and that's not always practical.

Implementors who think that SHOULD gives them a free pass to avoid implementing 
something that's needed to interoperate are misreading 2119.  But document 
editors should avoid using SHOULD for cases where failure to implement the 
requirement will result in interoperability failure.

I could see maybe posting an erratum or a brief update to 2119, but I think 
that reopening that document in general is a Very bad Idea.  And for existing 
documents that misuse SHOULD, the appropriate thing to do is to update those 
documents or post errata to those documents, rather than try to retroactively 
change the meaning of the keywords in those documents.

Keith

_______________________________________________
Ietf mailing list
Ietf@ietf.org
https://www.ietf.org/mailman/listinfo/ietf



_______________________________________________
Ietf mailing list
Ietf@ietf.org
https://www.ietf.org/mailman/listinfo/ietf
_______________________________________________
Ietf mailing list
Ietf@ietf.org
https://www.ietf.org/mailman/listinfo/ietf

Reply via email to