The square can represent:
• flowing water
Used to show a point of interest on maps (Nordic countries) It is the command (control) key on mac computers
St. John’s Arms Command Key (mac)
Saint Hannes cross
The looped square has been found on many items in Northern Europe, pre-dating the Christian period in Scandanavian countries.
In Finland, the symbol was used on homes, barns and housewares to protect the owners from evil spirits and bad luck. When the symbol is made with a rope, it is known as a Bowen knot (a heraldic knot for the Bowen family crest.)