We had this discussion while we were developing MODS in Dec. 2002-- see
the archives. I don't see any reason to rehash it. There was support for
allowing for both of these standards for encoding language.
ISO 639-2 IS a standard and widely used. It provides for many more
languages than ISO 639-1. Libraries have been using what is ISO 639-2 for
over 30 years in all flavors of MARC and this must be supported. The RFC
may alternatively be used.
I can give more information on the difference between the two, but it
might be sufficient just to look at the archives.
On Mon, 17 Jan 2005, Andrew E Switala wrote:
> Ack, speaking of not realizing things, I thought Internet language
> specifications were based on ISO 639-1 with an optional country code
> (e.g. en-US). Checking RFC 3066, I see this is not the case; xml:lang
> can be used for two-letter or three-letter language codes and more:
> - All 2-letter subtags are interpreted according to assignments found
> in ISO standard 639, "Code for the representation of names of
> languages" [ISO 639], or assignments subsequently made by the ISO
> 639 part 1 maintenance agency or governing standardization bodies.
> (Note: A revision is underway, and is expected to be released as
> ISO 639-1:2000)
> - All 3-letter subtags are interpreted according to assignments found
> in ISO 639 part 2, "Codes for the representation of names of
> languages -- Part 2: Alpha-3 code [ISO 639-2]", or assignments
> subsequently made by the ISO 639 part 2 maintenance agency or
> governing standardization bodies.
> - The value "i" is reserved for IANA-defined registrations
> - The value "x" is reserved for private use. Subtags of "x" shall
> not be registered by the IANA.
> - Other values shall not be assigned except by revision of this
> So I must agree, the MODS lang attribute can go.
> >>> [log in to unmask] 01/17/05 1:31 PM >>>
> On Jan 17, 2005, at 12:46 PM, Andrew E Switala wrote:
> > MODS guidelines say the lang attribute's value comes from ISO 639-2
> > bibliographic.
> I didn't realize this.
> > (The former is valid for the xml:lang attribute; why MODS has two
> > different language attributes is another matter.)
> But an important one. I don't understand this sort of thing. Why not
> just use THE xml standard for language coding, instead of once again
> relying on library-specific stuff?