<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<div class="moz-cite-prefix">On 26/06/2025 09:02, jeffb wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAANw6Q_pz_VT50LonuT0cdXiNwnyeLkyhB=7wNXo57cgL0hhEA@mail.gmail.com">
<div class="gmail_default" style="font-family:tahoma,sans-serif">Possibly
a good place to start: <a
href="https://datatracker.ietf.org/doc/html/rfc3490"
moz-do-not-send="true" class="moz-txt-link-freetext">https://datatracker.ietf.org/doc/html/rfc3490</a></div>
<div class="gmail_default" style="font-family:tahoma,sans-serif"><br>
</div>
<div class="gmail_default" style="font-family:tahoma,sans-serif">Specifically
Section 5.. though I have no idea how to register/who controls
ACE prefixes: <a
href="https://datatracker.ietf.org/doc/html/rfc3490#section-5"
moz-do-not-send="true" class="moz-txt-link-freetext">https://datatracker.ietf.org/doc/html/rfc3490#section-5</a></div>
</blockquote>
<p>Jeff,</p>
<p>Thanks.</p>
<p>It doesn't discuss <i>why</i> xn-- was chosen, though it does
say:</p>
<blockquote>
<pre class="newpage"
style="box-sizing: border-box; font-family: "Noto Sans Mono", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace; font-size: 16px; margin: -1.25em 0px 0px; display: block; overflow: visible; padding: 0px; width: 80ch; white-space: pre-wrap; color: rgb(33, 37, 41); font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); text-decoration-thickness: initial; text-decoration-style: initial; text-decoration-color: initial;">The ACE prefix, used in the conversion operations (<a
href="https://datatracker.ietf.org/doc/html/rfc3490#section-4"
style="box-sizing: border-box; color: rgb(13, 110, 253); text-decoration: underline;">section 4</a>), is two
alphanumeric ASCII characters followed by two hyphen-minuses. It
cannot be any of the prefixes already used in earlier documents,
which includes the following: "bl--", "bq--", "dq--", "lq--", "mq--",
"ra--", "wq--" and "zq--".</pre>
<p></p>
</blockquote>
<p>However, I couldn’t find a discussion of ACE prefixes, or how any
of the above were selected.</p>
<p>Gihan<br>
</p>
</body>
</html>