Neck of a 10-string E9-pedal steel guitar:
The fret marks guide the player to 12edo intervals, while the intervals between the strings are often tuned differently (i.e. just intervals, meantone tuning, various best-practice tunings)
↑Video 1: Webressource and licensing:
Wikimedia Commons
The original video is 3:14 minutes long. For demonstration purposes, an excerpt from 0:01 to 01:55 is shown here.