In the gforth documentation, at the bottom of section 13.5.1, are some confused statements. To quote:
> A special doubly indirect threaded version of the gforth executable is used > for creating the non-relocatable images; you can pass the exact filename of > this executable through the environment variable GFORTHD (default: > gforth-ditc); if you pass a version that is not doubly indirect threaded, you > will not get a fully relocatable image, but a data-relocatable image (because > there is no code address offset). The normal gforth executable is used for > creating the relocatable image; you can pass the exact filename of this > executable through the environment variable GFORTH. I think "not get a fully relocatable image," should be "not get a non-relocatable image,".