Forth include ?

[Leonard Zettel]

This undoubtedly is of no importance whatsoever,
natheless this inquiring mind would like to know.

The FreeBSD boot loader is written in Forth, which
I happen to be able to read (sort of, anyway).
EXCEPT the word "include" occurs in a number
of places. I grant it is fair to middling obvious what it
does. At the same time, I have not been able to find a definition
for include in any of the reference materials I have on
Forth. It is defninetly NOT ANS (or ISO) Forth (which specifies the
words INCLUDE-FILE and INCLUDED).

So 1) Can anybody give a stack picture for include ?
2) What version/dialect of Forth does FreeBSD use
and is there any place I can get documentation on it?

thanks in advance,
  -LenZ-