text: Glossary
  
  Stack notation: "<stack before> -- <stack after>". Rightmost is
  top of stack (TOS). For example, in "a b -- c d", b is TOS
  before, d is TOS after. "R:" means that the Return Stack is
  modified. "I:" prefix means "IMMEDIATE", that is, that this
  stack transformation is made at compile time.
  
  Word references (wordref): When we say we have a "word
  reference", it's a pointer to a word's *code link*. For example,
  the address that "' DUP" puts on the stack is a wordref, that
  is, a reference to the code link of the word DUP.
  
  PF: Parameter field. The area following the code link of a
  word. For example, "' H@ 1+" points to the PF of the word H@.
                                                          (cont.)
  