ld contain a list where the CAR is an <code><a
href="refI.html#idx">idx</a></code> tree of allowed items, and the CDR a list of
prefix strings. See also <code><a href="refA.html#allow">allow</a></code>,
<code><a href="refA.html#allowed">allowed</a></code> and <code><a
href="refP.html#pre?">pre?</a></code>.

<pre>
: (allowed ("app/")  # Initialize
   "!start" "!stop" "lib.css" "!psh" )
-> NIL
: (allow "!myFoo")  # additional item
-> "!myFoo"
: (allow "myDir/" T)  # additional prefix
-> "myDir/"

: *Allow
-> 