URGENT CANON QUESTION

Since my usual Ravenclaws are sleeping...  it's time for ASK THE F-LIST.  The question of the day is:

DO GHOSTS SHOW UP ON THE MARAUDER'S MAP?

I'm leaning toward NOT, because otherwise Harry would have been able to find Helena Ravenclaw, plus she would show up as "Helena Ravenclaw" instead of the Gray Lady.  Right?  Canon?  Theories?  HELP ME, FLIST, YOU'RE MY ONLY HOPE!  (I know, wrong fandom, but hey.)

:D

Also, hd_relief  starts prompting soon!  I'm not sure what time zone, yet, but we'll keep you posted.  Meanwhile, have fun putting Harry and Draco in a tree at hd_ina_tree .  

Someone make me do my taxes today, please?

CONSENSUS SO FAR:

YES, ghosts do show up on the map.  Thank you, everyone!