Section 4 in Kerala Survey and Boundaries Rules, 1964
4. Symbol for identification.
- The following symbols shall also be cut on theodolite and field stones to facilitate identifications.(a)on a theodolite stone at a village trijunction, a triangle one cm deep enclosing the plummet hole;(b)On a theodolite stone at any other point on the village boundary, two parallel lines one cm, deep one on either side of the plummet hole and parallel to the boundary line;(c)on a theodolite stone on a khandom boundary, a circle one cm, deep enclosing the plummet hole;(d)on all other theodolite stones a plummet hole one cm, deep on the top.(e)on a field stone on the boundary of a village plus mark (+) one cm deep on the top, and(f)all survey marks erected during town survey shall have in addition to the above marks a square of 7 cm side cut one cm, deep on the top.
