Question to those who use RS274X format...

If my company desided to use 3rd party software to convert standard gerber to
the newer RS274X format; What might a typical line in the file look like?
How are special "custom" apertures identified? Such as custom thermal flashes?

As I see it some kind of cross-reference file must still exist, in order to
identify these special custom flashes between the RS274X gerber and the actual
flash geometry?

Thus, the apertures are embedded somewhat, but not completely. The photoplot
operator will still have to identify each customers special apertures.


Presently, we send normal gerber files to our vendors. They cross-reference 
the dcodes to our documentation, which defines the physical size of each 
aperture. From there, after reading in our gerber files, they either enter in
the apertures manually or read in our customer aperture file. But still, custom
aperture sizes must be identified!


All info is appreciated.