MD 32 has waypoints for both its northern and southern junctions with MD 851. Usually, if we're going to ignore a route for being unsigned, we'd avoid (or delete) any references to the un-route in other routes' files, so that's a puzzle.
I added MD 717 in Upper Marlboro in April 2016. IIRC, the only signage for that route was at its south end, on BGSes for MD 4. MD 717 is short, but its north end is at another state route, and the only signage for MD 717 on that route is a "TO MD 4" assembly.
EDIT:
MDRoads shows the now-signed MD 851 through Sykesville as one of eight former MD 32 segments (many MD 8xx routes are old alignments remaining in the state DOT's inventory). All the other segments are less than a mile long. I'll ignore the other segments, unless any of them turn out to be signed as well.
I can add MD 851 to the HB, if there is no objection.