Re: [dmarc-ietf] Nitpicky questions about DMARC record syntax

Dave Crocker <> Wed, 16 January 2019 15:38 UTC

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To: John R Levine <>
References: <20190116005804.A0A80200CACDA9@ary.qy> <> <alpine.OSX.2.21.1901161029520.36401@ary.qy>
From: Dave Crocker <>
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Date: Wed, 16 Jan 2019 07:38:29 -0800
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Subject: Re: [dmarc-ietf] Nitpicky questions about DMARC record syntax
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On 1/16/2019 7:30 AM, John R Levine wrote:
>> The formal specification is quite clear on both of your questions:
>>   Section 6.4:
>>   dmarc-version   = "v" *WSP "=" *WSP %x44 %x4d %x41 %x52 %x43 %x31
>> which means that the white space is required to be allowed and the 
>> value in this tag-value is case sensitive.
> Thanks, but the white space in question is before the "v".

The ABNF rule I included, and the one that cites it (dmarc-record) do 
not show any white space permitted before the 'v', so no it's not legal.

So the formalities are quite clear on both your questions.

Whether there is benefit or detriment in making the parser more robust 
than the formal rules define goes to the heart of the last point in your 
original note.


Dave Crocker
Brandenburg InternetWorking