<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
h3
{mso-style-priority:9;
mso-style-link:"Heading 3 Char";
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:13.5pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{mso-style-priority:99;
mso-style-link:"Plain Text Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.5pt;
font-family:Consolas;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.PlainTextChar
{mso-style-name:"Plain Text Char";
mso-style-priority:99;
mso-style-link:"Plain Text";
font-family:Consolas;}
span.Heading3Char
{mso-style-name:"Heading 3 Char";
mso-style-priority:9;
mso-style-link:"Heading 3";
font-family:"Times New Roman","serif";
font-weight:bold;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-AU link=blue vlink=purple>
<div class=WordSection1>
<p class=MsoPlainText>My attention has been drawn to SpatialReference.org.<o:p></o:p></p>
<p class=MsoPlainText>I understand that the goal is to provide URL-based links
to SRS definitions.<o:p></o:p></p>
<p class=MsoPlainText>I also see that you have coined names like <a
href="http://spatialreference.org/ref/epsg/4326/">http://spatialreference.org/ref/epsg/4326/</a>
for entries in the EPSG database.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>You may be interested to know that OGC recently revised
its polices in this area[1], and is now maintaining URL references for all of
the EPSG database. <o:p></o:p></p>
<p class=MsoPlainText>For example, try <a
href="http://www.opengis.net/def/crs/EPSG/0/4326">http://www.opengis.net/def/crs/EPSG/0/4326</a><o:p></o:p></p>
<p class=MsoPlainText>The URL pattern is actually just a mapping from the URN
syntax previously used by OGC[2].<o:p></o:p></p>
<p class=MsoPlainText>Hence the /0/ element in the URL just indicates
‘unversioned’ entries, and the OGC service gets the data from EPSG
by re-writing the URL into the request-with-argument expected by EPSG.<o:p></o:p></p>
<p class=MsoPlainText><o:p> </o:p></p>
<p class=MsoPlainText>I expect you will be pleased that OGC is now taking on
the job of providing persistent URLs for resources that it maintains or for
which there is an agreement with the owner.<o:p></o:p></p>
<p class=MsoPlainText>In my role as chair of the OGC Naming Authority I am
pushing for OGC to understand and support the implications of this across an
increasing array of OGC resources.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Simon<o:p></o:p></p>
<h3><span style='font-size:10.0pt;font-family:Consolas;font-weight:normal'>[1] OGC-NA
Name type specification - definitions: Part 1 - basic name <a
href="http://portal.opengeospatial.org/files/?artifact_id=37802">http://portal.opengeospatial.org/files/?artifact_id=37802</a>
<o:p></o:p></span></h3>
<h3><span style='font-size:10.0pt;font-family:Consolas;font-weight:normal'>[2] OGC
Naming Authority (OGC-NA) Policies & Procedures <span class=MsoHyperlink><a
href="http://portal.opengeospatial.org/files/?artifact_id=37800">http://portal.opengeospatial.org/files/?artifact_id=37800</a></span>
<o:p></o:p></span></h3>
<p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b><span
style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#0099CC'>Simon
Cox</span></b><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'><br>
</span><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Research
Scientist<br>
CSIRO Earth Science & Resource Engineering<b><span style='color:#0099CC'><o:p></o:p></span></b></span></p>
<p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial","sans-serif"'>Phone:
+61 8 6436 8639<b><span style='color:#BED600'> | </span></b>Fax:
+61 8 6436 8555 <b><span style='color:#BED600'>|</span></b> Mobile:
0403 302 672<br>
<span style='color:#0099CC'><a href="mailto:lyndelle.broadfoot@csiro.au"><span
style='color:blue'>simon.cox@csiro.au</span></a></span> <b><span
style='color:#BED600'>|</span></b> <span style='color:#0099CC'><a
href="http://www.csiro.au"><span style='color:blue'>www.csiro.au</span></a></span><br>
Address: <span style='color:#999999'>ARRC, PO Box 1130, Bentley, WA 6102,
Australia</span><br>
<br>
</span><o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
</div>
</body>
</html>