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Symbols within a rectangle indicate a military unit, within a triangle an observation post, and within a circle a supply point.
Military Units - Identification
The following symbols placed either in boundary lines or above the rectangle, triangle, or circle inclosing the identifying arm or service symbol indicate the size of military organization:
The letter or number to the left of the symbol indicates the unit designation; that to the right, the designation of the parent unit to which it belongs. Letters or numbers above or below boundary lines designate the units separated by the lines:
Various Conversions (Temperature, Volume, Weight, Length, Clothing Conversion...) :
United States - state abbreviations :