Dear Bug Team! Phillip Lord <p.lord(a)russet.org.uk&gt; pointed this out on comp.emacs.xemacs. He says: Since this is part of the Common Lisp library, I checked out the relevant Common Lisp spec. The X3J13 SUBSEQ-OUT-OF-BOUNDS cleanup notes that the original spec did not address this issue, and requires that an error be thrown. Since that is what we are doing, I agree with Phillip that this is a documentation bug. Note that the relevant info page also does not specify the behavior in this case. -- Jerry James http://www.ittc.ku.edu/~james/