Language subtag registration for acor1990 (ammended from ao1990)

Philip Newton philip.newton at
Thu Aug 25 16:10:32 CEST 2011

2011/8/25 "António H F P A Emiliano (FCSH/UNL)" <ah.emiliano at>:
> i) can anyone please provide me with precedents and similes?

You may wish to have a look at and search
for "Type: variant" (very near the end of the file). That will find a
number of variant subtags, some of which historical language forms or
orthographies. For example, the first couple of variant subtags start
with numbers denoting a year; a bit later, there is "baku1926" which
also contains a year, and "luna1918" / "petr1708" even later.

> ii) were similar subtags created recently for reformed Dutch and German?

For German, yes: the subtag "1996" refers to "German orthography of
1996". The pre-1996 orthography has the subtag "1901", with a current
description of "Traditional German orthography".

I'm not sure where the discussion that led to this subtag, or the
submission record for the subtag, are archived, though.

I don't know whether there is a subtag for a Dutch spelling reform.

> iii) can anyone please direct me to a document that states the formal
> requirements of a language subtag of this kind?

RFC 5646, available (for example) at , is probably the best place to

Philip Newton <philip.newton at>

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