Re: [Lager] Stephen Farrell's Discuss on draft-ietf-lager-specification-11: (with DISCUSS and COMMENT)

"Asmus Freytag (c)" <> Fri, 29 April 2016 17:27 UTC

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To: Stephen Farrell <>, Alexey Melnikov <>
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From: "Asmus Freytag (c)" <>
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Subject: Re: [Lager] Stephen Farrell's Discuss on draft-ietf-lager-specification-11: (with DISCUSS and COMMENT)
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On 4/29/2016 9:53 AM, Stephen Farrell wrote:
> (Sorry on the way out the door, and I may owe you more of a response
> but I noticed this...)
> On 29/04/16 17:36, Asmus Freytag (c) wrote:
>> As XML is case-sensitive, an LGR must be authored with the correct
>> casing. For example, the XML element names MUST be in lower case as
>> described in this specification, and matching of attribute values, is
>> only performed in a case-sensitive manner.
> That's an odd example though. Surely the more likely way to get
> a non-validating is more like the one I called out where a code
> point omits leading zeros or similar?

I think we do not want to repeat all the constraints from the schema in 
this introductory section.

Casing was mentioned by somebody in a different comment, so this text 
was added in an earlier round
and should have been in the version you reviewed. I think it is a useful 
reminder of the case-sensitive
nature of XML document parsing, but, like the issue you raised, really 
is already implicit in the fact that the
specification is about defining an XML-based, schema-validated 

The new text in response to your comment focuses on the schema. The number
format is described in the schema via a pattern, as in:

## a single code point
code-point = xsd:token {
     pattern = "[0-9A-F]{4,6}"

I believe that the existing language in the spec (where the effect of 
the pattern is described in
words) together with the pattern in the schema is sufficient to make 
clear that "01" is not
valid while "0001" is.

The new text in section 4 serves the purpose to act as a general 
reminder that documents that
fail the schema validation must be rejected. Like the casing issue, this 
reminder is intended to
be helpful, but one can argue that it isn't strictly needed.