symbol
Plumb mark
A plumb-line emblem of uprightness in craft speech. Not published plumb-bob or plumb-rule alone, and not level-mark.
Also known as Plumb emblem · Plumb line mark
symbol
A plumb-line emblem of uprightness in craft speech. Not published plumb-bob or plumb-rule alone, and not level-mark.
Also known as Plumb emblem · Plumb line mark