[tz] technical details for today's code and data release

[John Hawkinson]

> But it seems to indicate that we should go with two-faceted tags
> (tz_codeX_dataY), to make this clear.

I'd disagree.
That would mean that to check out codeX, you would need to enumerate
the list of tags to determine a matchign dataY.

Better, I think, to have a codeX tag and a dataY tag and suffer the
fact that a checkout of one will give you a
close-but-potentially-unexpected other.

--jhawk at mit.edu
  John Hawkinson