it is still kind of sad that one of the canonical references of the Lisp "community" is a non-free, not even any Creative Commons document, that cannot be updated or maintained by said users.
You could use the last draft of the ANSI Common Lisp standard instead. The last draft is probably in the public domain. You could update and build upon that instead. Look up "Version 15.17R, X3J13/94-101R" of the proposed ANSI Common Lisp standard.