Add additional information to class tag in SVG

Hello,

I need additional information in an SVG e.g. not only the position of a notehead but also to what pitch it corresponds and its duration etc. I know this could be extracted from the SVG but that is very cumbersome.

I thought of extending the class label in the SVG. So instead of just writing class="Note", I would like to write class="Note C1 - 1/4" or something like that.

Can anyone point me to the part of the code where these class labels are set or what I'd need to change in the code? I guess this functionality can not be done via a plugin or can it?

Thanks for your help