I'm trying to create a custom symbol using inkscape and editing the svg file to be able to manage it from the style window in QGIS.
Edited the .svg symbol file deleting the "style" lines and inserting the line (after "path" and "circle"):
fill="param(fill) #FFF" stroke="param(outline) #000" stroke-width="param(outline-width) 1"
I can edit lines colors/thicknesses and the fill color but I do not know how to edit file to get a transparent fill of the symbol. How can i fix it?