A friend of mine, noting that Wikipedia uses SVG images for diagrams, asked if it also had some written guidelines for how to write the SVG source code, in particular to express measurement values in the original units rather than on a pixel scale. He had found some SVG diagram that made a curve from 140 pixels to 190 pixels, rather than from 7 million to 9.5 million inhabitants, which was the unit that the y axis displayed. (Or something like that.)
I said "probably not, your thinking is likely 5 years ahead of the Wikipedia community".
As this all happened in April 2009, he came back yesterday to ask where we are now.
Do we have any guidelines for how to hand-write the source code of SVG diagrams? Should we?
Maybe this is related to Wikidata?