Word name storage quirk in VAX fig-Forth

I've been dusting-off fig-Forth for VAX-11 and noticed that every word
in the dictionary has 128 added to the character code of the last
character in the word name. Everything seems to work except a few things
like VLIST (prints a list of defined words like WORDS in ANS Forth)
printing a garbage character at the end of each word.

I wrote my own version of VLIST to unmunge the last characters, but it's
hard to believe it's been messed up for 40 years. Is there some
peculiarity in fig-Forth or the VAX-11 (I'm using significantly later
hardware and OS) that made this work correctly back in the day?

--
David Meyer
Takarazuka, Japan
papa@sdf.org