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<p>I don't think so. Where do we need null values in OSM?</p>
<p>As you said, maxspeed=none means something like maxspeed=unlimited.</p>
<p>I can't think of any tag key which should be stored in OSM with a null value. <br>
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<p>In what case would that add valud information compared to having no such tag ?<br>
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<p>Gerd<br>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt" color="#000000" face="Calibri, sans-serif"><b>Von:</b> Colin Smale <colin.smale@xs4all.nl><br>
<b>Gesendet:</b> Sonntag, 24. Januar 2016 10:58<br>
<b>An:</b> Tag discussion, strategy and related tools; Tijmen Stam<br>
<b>Betreff:</b> Re: [Tagging] Removing name_1 and alt_name_1 from Wiki</font>
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<div>At present the string "none" is actually a value, the interpretation of which is specific to the key "maxspeed" . Maybe we should promote it to the equivalent of NULL in SQL.
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<div class="gmail_quote">On 24 January 2016 10:43:16 CET, Tijmen Stam <mailinglists@iivq.net> wrote:
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<pre class="k9mail">With the value "none"<br><br>For example on German Autobahnen, where you can drive as fast as you <br>want is "maxspeed=none" which is different from having maxspeed not set: <br>this means maxspeed is unknown or not tagged yet.<br><br><br><br>On 20-01-16 09:06, Colin Smale wrote:<br><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex; border-left:1px solid #729fcf; padding-left:1ex"> Exactly.<br><br> If a missing value (i.e. use the default) is not the same as explicitly<br> having NO value, how do you override the default with "no value"?<br><br> --colin<br><br> On 2016-01-20 08:50, Gerd Petermann wrote:<br><br><blockquote class="gmail_quote" style="margin:0pt 0pt 1ex 0.8ex; border-left:1px solid #ad7fa8; padding-left:1ex"> I don't think that the meaning really depends on the position. My<br> understanding is that the<br><br> complete value (e.g. "80||" ) is parsed by splitting it into separate<br>
strings at each pipe symbol.<br><br> Result: three strings: "80" , "",""<br><br> The value "|80|" also gives three strings: "","80",""<br><br> Another point is that an empty value means "use the default", which can<br><br> only make sense in special cases like this.<br><br> Gerd<br><br><br><hr><br> *Von:* Colin Smale <colin.smale@xs4all.nl><br> *Gesendet:* Mittwoch, 20. Januar 2016 08:23<br> *An:* Tag discussion, strategy and related tools<br> *Betreff:* Re: [Tagging] Removing name_1 and alt_name_1 from Wiki<br><br> I meant that there is a value missing "between the pipes", which at a<br> slightly higher semantic level can mean "use the default". A<br> definition which varies according to position doesn't feel well-formed<br> to me.<br><br> //colin<br><br> On 2016-01-20 08:10, Gerd Petermann wrote:<br><br> Colin Smale wrote<br><br> The "lanes" tag family uses a different delimiter ("|"), sometimes<br>
together with a semicolon to make a kind of 2-d array. A<br> double pipe<br> ("||") indicates a missing value there. Wouldn't it be nice if<br> we were<br> consistent?<br><br><br> That is new to me. My understanding of a double pipe is that<br> described here:<br> <a id="LPlnk897821" href="http://wiki.openstreetmap.org/wiki/Proposed_features/lanes_General_Extension#Default_values">http://wiki.openstreetmap.org/wiki/Proposed_features/lanes_General_Extension#Default_values</a><div style="margin-bottom: 20px; overflow: auto; width: 100%;" id="LPBorder_GT_14536301283730.3193158707318221"><table style="width: 90%; background-color: rgb(255, 255, 255); position: relative; overflow: auto; padding-top: 20px; padding-bottom: 20px; margin-top: 20px; border-top: 1px dotted rgb(200, 200, 200); border-bottom: 1px dotted rgb(200, 200, 200);" id="LPContainer_14536301283670.44698951543001" cellspacing="0"><tbody><tr style="border-spacing: 0px;" valign="top"><td colspan="2" style="vertical-align: top; position: relative; padding: 0px; display: table-cell;" id="TextCell_14536301283690.8655412649043254"><div id="LPRemovePreviewContainer_14536301283690.9725637770800837"></div><div style="top: 0px; color: rgb(0, 120, 215); font-weight: 400; font-size: 21px; font-family: "wf_segoe-ui_light","Segoe UI Light","Segoe WP Light","Segoe UI","Segoe WP",Tahoma,Arial,sans-serif; line-height: 21px;" id="LPTitle_14536301283690.2637965891970432"><a target="_blank" href="http://wiki.openstreetmap.org/wiki/Proposed_features/lanes_General_Extension#Default_values" style="text-decoration: none;" id="LPUrlAnchor_14536301283700.4890155291038948">Proposed
features/lanes General Extension - OpenStreetMap Wiki</a></div><div style="margin: 10px 0px 16px; color: rgb(102, 102, 102); font-weight: 400; font-family: "wf_segoe-ui_normal","Segoe UI","Segoe WP",Tahoma,Arial,sans-serif; font-size: 14px; line-height: 14px;" id="LPMetadata_14536301283710.14335180821845606">wiki.openstreetmap.org</div><div style="display: block; color: rgb(102, 102, 102); font-weight: 400; font-family: "wf_segoe-ui_normal","Segoe UI","Segoe WP",Tahoma,Arial,sans-serif; font-size: 14px; line-height: 20px; max-height: 100px; overflow: hidden;" id="LPDescription_14536301283720.6505912997183171">A
simple, straightforward extension of existing tags to specify properties not only for a way as whole but for the lanes of the way instead. Based on this general ...</div></td></tr></tbody></table></div><br><br> Proposed features/lanes General Extension - OpenStreetMap Wiki<br> <<a href="http://wiki.openstreetmap.org/wiki/Proposed_features/lanes_General_Extension#Default_values">http://wiki.openstreetmap.org/wiki/Proposed_features/lanes_General_Extension#Default_values</a>><br> <a href="http://wiki.openstreetmap.org">wiki.openstreetmap.org</a><br> A simple, straightforward extension of existing tags to specify<br>
properties not only for a way as whole but for the lanes of the<br> way instead. Based on this general ...<br><br><br> which indicates that a double pipe means one or two default values,<br> depending on the position.<br> At the end of the value, it means two default values.<br><br> Gerd<br><br><br><br> --<br> View this message in context:<br> <a href="http://gis.19327.n5.nabble.com/Removing-name-1-and-alt-name-1-from-Wiki-tp5864465p5865207.html">http://gis.19327.n5.nabble.com/Removing-name-1-and-alt-name-1-from-Wiki-tp5864465p5865207.html</a><br> <<a href="http://gis.19327.n5.nabble.com/Removing-name-1-and-alt-name-1-from-Wiki-tp5864465p5865207.html">http://gis.19327.n5.nabble.com/Removing-name-1-and-alt-name-1-from-Wiki-tp5864465p5865207.html</a>><br> Sent from the Tagging mailing list archive at <a href="http://Nabble.com">Nabble.com</a>.<br><br><hr><br> Tagging mailing list<br>
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