Andreas-- interesting question. I did a bit of searching on the net. The small cutouts were used to provide light and ventilation, and were generally placed above the line of sight for privacy. The reason for the moon shape in the US is that the moon is a traditional symbol for female while the sun is a traditional symbol for male. The sun and moon were used to distinguish the men's and women's outhouses during a time when many people were illiterate. Men's outhouses tended to fall into disrepair/disgusting filth more rapidly than the female bathrooms, so everyone eventually started using the ladies' room, and the moon symbol became common on most/all outhouses. Don't know if it's true or not, but certainly an interesting explanation.
Bruise-- toothbrush??? toothbrush??!?! That just about made me toss my lunch:barf: :barf:
---Josh