<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>François,</p>
<p>The discussion about this has also been brought to the forum,
here: <a class="moz-txt-link-freetext" href="https://forum.openstreetmap.org/viewtopic.php?id=64825">https://forum.openstreetmap.org/viewtopic.php?id=64825</a></p>
<p>I'm unsure if it is better to continue it here in the ML, there
in the forum, or in both places...</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 2018-12-20 01:04, François Lacombe
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAG0ygLdmQEDqumihpqxCAnefkUVJtgCZjVWC1DLFQnLBMmpckA@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div dir="ltr"><br>
<div class="gmail_quote">
<div dir="ltr">Le mer. 19 déc. 2018 à 22:26, Richard <<a
href="mailto:ricoz.osm@gmail.com" moz-do-not-send="true">ricoz.osm@gmail.com</a>>
a écrit :<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">the OSM tag chain should
be imho used only for very common things because each member
<br>
of the chain will turn up as a "top level" tag in the
database and taginfo. <br>
</blockquote>
<div><br>
</div>
<div>We are using such chains in Power, Pipeline and Telecom
groups. It works well :<br>
</div>
<div>power=transformer + transformer=distribution +
voltage:primary=20000 + voltage:secondary=400</div>
<div>man_made=street_cabinet + street_cabinet=telecom +
telecom=exchange + telecom:medium=copper + operator=Orange</div>
</div>
</div>
</blockquote>
<p><br>
</p>
<p>"Transformers" is a perfect example of "namespacing done
backward". Why "voltage:secondary=220"? In a correctly namespaced
world it would be "secondary:voltage=220".</p>
I understand that in spoken English you can say "the <b><b>voltage</b></b>
of the <b>secondary </b>is <b>220 </b>Volt", and that's probably
why those keys have been built with the terms in that particular
order. (<i>BTW, logic and wording is very different in different
cultures and languages. I think it wouldn't had been in that order
in, say, German: can a german speaker please confirm that?</i>)<br>
<p>Transformers can have and very often have more than one
secondary: you have dealt with that using things like
"voltage:tertiary=*" and the likes (windings:tertiary=*, I
suppose...). And what if the transformer has 3 secondaries? Or 4?<br>
</p>
<p>Isn't "secondary:1:voltage=200" better? Don't you see that's more
logical and expandable? Don't you see that here we assign a
quantity (220) to something that has the correct dimensions
(voltage), like in the previously globally defined key
"voltage=*"? Don't you see how with that syntax everything related
to the first (<i>second, third, fourth,... nth</i>) secondary (<i>wingdings,
current, whatever...</i>) would be grouped under
"secondary:n:*="?<br>
</p>
<p>And if transformers weren't meant to be a "<i>namespaced thing</i>",
why using the columns? Why not voltage_secondary=* ?<br>
</p>
<p>Don't you see that with the transformers a <b>new first level
keyword</b>, "rating=*" have been implicitly defined and
documented in the transformers page and how that keyword can be
useful in other contexts... or namespaces, if you prefer?<br>
</p>
<p><br>
</p>
<p>BTW, what is that telecom:medium=copper thing
(<a class="moz-txt-link-freetext" href="https://wiki.openstreetmap.org/wiki/Key:telecom:medium">https://wiki.openstreetmap.org/wiki/Key:telecom:medium</a>)? <i>"Telecoms"
</i>do not have a medium: local loops have. Is that meant to be
a namespaced thing? Have this being debated/approved? I have seen
it applied to buildings: what is the meaning of that?<br>
</p>
<p><br>
</p>
<blockquote type="cite"
cite="mid:CAG0ygLdmQEDqumihpqxCAnefkUVJtgCZjVWC1DLFQnLBMmpckA@mail.gmail.com">
<div dir="ltr">
<div class="gmail_quote">
<div>Adding power: and telecom: prefixes would be seriously
bad to encourage for contribution and extremely redundant.</div>
</div>
</div>
</blockquote>
<p><br>
</p>
<p>To the contrary! Please read in the forum my rationale explaining
exactly how that would be beneficial...</p>
<p><br>
</p>
<blockquote type="cite"
cite="mid:CAG0ygLdmQEDqumihpqxCAnefkUVJtgCZjVWC1DLFQnLBMmpckA@mail.gmail.com">
<div dir="ltr">
<div class="gmail_quote">
<div><br>
</div>
<div>Furthermore, refining of well used tags often get
discouraged because of their usage.<br>
</div>
<div>This dosn't include the redundancy in namespaces'
prefixes which is worse.</div>
<div> </div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px
0.8ex;border-left:1px solid
rgb(204,204,204);padding-left:1ex">
If used extensively for attributes I would consider it
polution of the database.<br>
It is also much less flexible as you can specify only one
attribute at a time.<br>
</blockquote>
<div>If you have to define more than one attribute with the
same name it may be the attribute isn't weel defined.</div>
<div><br>
</div>
<div>Have you examples please?</div>
<div><br>
</div>
<div>All the best</div>
<div><br>
</div>
<div>François</div>
</div>
</div>
</blockquote>
<p><br>
</p>
<p>Sorry, I'm really now on the verge (<i>less than 24 hours...</i>)
of a small journey, so I would probably be unable to
answer/contribute anymore until January, 6.</p>
<p>Cheers,</p>
<p>Sergio<br>
</p>
</body>
</html>