Knob documentation for all parameters?

Is there any documentation available regarding the parameters?
I just found this: https://www.openhab.org/docs/configuration/habpanel.html#knob-knob

I did some try & error with all the settings (e.g. bar, track, width, cap) - but I couldn’t figure out what they are really doing. Are there some correlations like padding and width do have in HTML?