Version 1.3 is the first one that provides all ANS Forth word sets, except
for 17 words that had to be omitted for various reasons:

?DUP
Ambiguous stack effect.

PICK ROLL
Ambiguous stack effect with respect to data types.

(
Used for stack diagrams instead of for comments.

FIND
Replaced by SEARCH-ALL, because of ambiguous stack effect and usage of
counted strings.

C" COUNT WORD
Counted strings are not supported. WORD has been replaced by PARSE-WORD.

CS-PICK CS-ROLL
Not required because StrongForth does not need a separate control-flow
stack.

RESIZE-FILE
Missing support by DOS.

UNLOOP
Not required, because loop indexes are locals.

CONVERT EXPECT FORGET QUERY SPAN
Declared obsolet by the standard.

StrongForth is not ANS compatible, because all definitions that have an
actual stack effect require an explicit stack diagram. Furthermore, the
semantics of some words had to be modified, and several words got renamed.
Renaming is mostly caused by overloading. For example, + D+ M+ and F+ share
the same name +, because the compiler and interpreter can easily select the
correct version based on the data types. As a result, only 272 different
names are required to implement ANS Forth words with 342 (359 - 17)
different names.