[GRASSLIST:7700] Raster placement coordinates formatting

[Bart]

Hey all,


I've been testing my export code and hit on a problem,
namely the referencing of rasters that I export.
Right now I do an r.out.ascii and read the header, 
which essentially gives me the data from the cellhd
directory, specifically north, east, south and west
for a map.

I would like to know what is the various formats 
these can be in, and specifically how negative values
are encoded in each and what non-number data
may be in there. The variation seems to stem from 
the proj element, which can apparently be 
unreferenced (0), UTM (1), state plane (2) and
lat-long (3). Is this true?

--Bart