This extension sets a CSS class on elements selected in Inkscape. It optionally clears their inline styles, in order for the CSS styling to have effect.
This works well in conjunction with "Merge Styles into CSS".
Use the included setup.py script:
python setup.py install
or manually copy the files set_css_class.inx and set_css_class.py to your Inkscape extensions directory.
On Unix-like systems (including Linux and Mac OS X) this is usually ~/.config/inkscape/extensions and on Windows it is %APPDATA%\inkscape\extensions.
Select objects in the document, and in the menu select Extensions->Set CSS class on elements.
GPL-2.0