what does "inkscape:" in .SVG mean?

Question

I know this is trivial but hopefully this proves to be helpful to others aside from just myself.

I keep finding this attribute in the .SVG I am working on: "inkscape:". What does it mean? Then abstracting it out one level what does "anything:" mean when declared as an attribute of a .SVG? eg.

inkscape:lblTemplate="{align:Right,attr:get,tag:tag,type:Good}"     zoomAndPan="magnify" xmlns:xlink="http://www.w3.org/1999/xlink" inkscape:vyplnStroke="txtcolor" xmlns:rtda="http://www.itris.fr/2003/animation" contentStyleType="text/css" id="text0243" version="1.0" width="100" xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape" inkscape:opac="ver;1;1" preserveAspectRatio="xMidYMid meet" inkscape:textik="max.toFixed(dp)" viewBox="0 0 100 300" height="300" xmlns="http://www.w3.org/2000/svg" inkscape:componentData="{name:B - T Bar,desc:Bottom - Top Bar,author:mySCADA Team,uniqueID:0348f7cec3,list:[{variableName:tag,name:tag,desc:Tag,value:tag,type:0},{variableName:min,name:min,desc:Min,value:0,type:2},{variableName:max,name:max,desc:Max,value:100,type:2},{variableName:color1,name:color-low,desc:Low color,value:#FFFF00,type:4},{variableName:color2,name:color-norm,desc:Normal color,value:#00FF00,type:4},{variableName:color3,name:color-high,desc:High color,value:#FF0000,type:4},{variableName:txtcolor,name:,desc:Text color,value:#000000,type:4},{variableName:TH1,name:treshold1,desc:1st treshold,value:25,type:2},{variableName:TH2,name:treshold2,desc:2nd treshold,value:75,type:2},{variableName:label,name:label,desc:Label,value:Label,type:1},{variableName:fsize,name:fsize,desc:Font size,value:12,type:2},{variableName:dp,name:,desc:No. of decimal places,value:1,type:2}]}"

or

inkscape:vypln="txtcolor"

Both above examples are inline with the tag, as in before the ">" in .

Answer 1

It means that the attribute is within an XML namespace. It is a way of extending the definition of an XML schema without changing the original, that is, maintaining compatibility, i.e. other programs may ignore those attributes.

If you look at the top of the file you'll see a more complete specification of what namespace that "inkscape:" prefix refers to.

In this case, it is obviously some extension related to the Inkscape SVG-editing program.