I believe that keyword arguments are considered an extension. Still, that is implemented, so I defer.
Assuming you're talking about Common Lisp, keywords alone and keywords as argument specifiers are AFAIK both required parts of the spec, not just optional extensions. Other Lisp dialects can and do have different ideas - the only other relatively widely used Lisps, these days, are Scheme and Emacs Lisp (which both don't have keyword args).

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re^9: When every microsecond counts: Parsing subroutine parameters by Joost
in thread When every microsecond counts: Parsing subroutine parameters by snowhare

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.