This sign, the
horizontal rectangle was used already by the Egyptians, where it meant
garden pool. Today it is found in some 20 ideographic systems
and basically denotes an enclosed space, tank, or closed room. Since often signifies
heat, it follows that can mean heat
oven in some technical contexts.
As a genealogical sign means buried.
In Diderot's Encyclopedia it is recorded as one of the signs for magnet.
In the British and Swedish systems of hobo signs means danger, people living here will try to have you arrested, and the owner of this house is a brute, respectively. See in Group 22 and in Group 34, both of which have a similar meaning.