Registry fixed (was: Re: Records Missing Required Field: jkp, nph, tvt)

Doug Ewell doug at
Wed Aug 29 04:27:10 CEST 2012

Gordon P. Hemsley wrote:

> It seems to me that the true ABNF defines the basic or primary syntax,
> and the prose defines some sort of secondary syntax or even semantics.
> (If you wrote a parser based only the ABNF, for example, there would
> have been no violation wrt to the missing Added fields.) This ABNF can
> be used to create a registry of many things, not just language
> subtags. It's only the prose that limits which fields are required in
> order to have a valid record.

It would be pretty useless to have a record with no Description field, 
or with zero or two Type or Subtag/Tag fields, or with a Razzle field, 
or with a Type value of "dazzle", or with an Added value of 
"2012-06-31",  or two records with the same Subtag/Tag value, or a 
script or region subtag record with a Scope or Macrolanguage or 
Suppress-Script field, etc. etc.

> Consider future developments: The requirement or optionality of fields
> could easily be changed via prose without having to change the ABNF at
> all. Thus, a new parser could still parse an old version of the
> Registry—or, on the flipside, an old parser could still parse a new
> Registry—even if the prose requirements were different.

An ABNF-only parser that accepted any of the anomalies listed above 
wouldn't be worth much, in my opinion.

> But I too am curious as to what the original authors had in mind.

Thanks to Addison for entering the fray.

Doug Ewell | Thornton, Colorado, USA | @DougEwell ­ 

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