On Thu, 15 Apr 2004, Ulf Andersson wrote:
  The standard you are looking for is named EIA-247 and
is found at
 
global.ihs.com
 to the hefty price of USD 78.00. It's somewhat hard to find the standard by
 using
 Google or something, but trying out "gerber file format" and
"RS-274-D" gave
 enough leads to start a manual hunt at the standards institutes.
 Things to look out for:
   EIA-274-D   The TIA/EIA standard
   ISO 6983    The ISO version (same thing in an ISO wrapper)
 
The document that used to be at Barco (rs274xrevd_e.pdf) is gone but a copy
was easily found using ftp search. Also both PCB and GERBV can output RS274 so
you might look at the source from those programs
Snip--------------------------
Peter Wallace
Mesa Electronics