<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<br>
<blockquote
cite="mid:CAF63+7WjtN_jdrM56F4KybFH+v6N0pmT+Pk_=Rq4G5barcOdAg@mail.gmail.com"
type="cite">
<div id="ygrp-mlmsg" style="position:relative;">
<div id="ygrp-msg" style="z-index: 1;">
<div id="ygrp-text">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div>In reality, font designers do care to have
language specific behavior when **the engine** has
no idea of the script. Mapping U+06F7 EXTENDED
ARABIC-INDIC DIGIT SEVEN to the Urdu style under
lang=ur even if the digit (script=Common) is
standing alone by itself is a perfectly legitimate
example of wanting DFLT:urd.<br>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
</blockquote>
<br>
The locale "ur" is "completed" to "ur_Arab_PK" by likely subtags,
and therefore I would process a string tagged with locale "ur" and
containing only Common character to arab/URD.<br>
<br>
In my mind, DFLT was never intended to be specified by the user of
the font, no more than there is a specific way to say "use
defaultLangSys". <br>
<br>
Eric.<br>
<br>
</body>
</html>