Request for variant subtag fr 16th-c 17th-c Resubmitted!

[Ciarán Ó Duibhín]

I'd like to pick up on something Peter Constable said a while back when I
asked about tagging language varieties which span the boundaries between ISO
639 languages.

I wrote:
<<As a linear list of languages, ISO 639 may divide up varieties which
belong together from another point of view, and which would be kept together
in a different linear classification.>>
and Peter replied:
<<Categories with scope = macrolanguage, as introduced with ISO 639-3, exist
for this very purpose.>>

At first sight macrolanguages looks like the proverbial sledgehammer for
this purpose.  But let me guess how it could work (for the historical French
example we have been considering).  We create a macrolanguage containing
"fr" and "frm", and probably "fro".  We create a subtag for the overlapping
area, and make it a subtag of the macrolanguage, but not of fr, frm or fro
individually.  If allowable, this would seem to meet the need.  It is
attractive in that it avoids having to tag an overlap text as fr or frm,
which may appear to the tagger to be a meaningless operation.

Is this mechanism technically acceptable?  If so, I suggest we examine the
consequences of making "16siecle" and "17siecle" subtags of a French
macrolanguage tag.  If not, had Peter some other macrolanguage mechanism in
mind?  Otherwise, it will be back to discussion of the subtag method.

Ciarán Ó Duibhín.