If an old version of the MGF parser encounters new entities it does
not recognize, the default action is to ignore them, printing a warning
message.
This may be overridden to support custom entities, but such
practice is discouraged because it weakens the standard.
To obtain the latest version of this standard for luminaire data, write to:
Illuminating Engineering Society of North America
345 East 47th St.
New York, NY 10017.
A name in MGF is any sequence of printing, non-white ASCII characters
beginning with a letter.
For systems that
are sensitive to seam position, it is probably safest for their MGF
loader/translator to re-expresses seams in terms of holes again, which can
be done easily so long as vertices are shared in the fashion shown.