What Points are To Be Connected To Earth?

What Points are To Be Connected To Earth? Points : what points are to be connected to earth? The following equipment should be connected to earthing through earth wire as per Electricity Rules.

i) The neutral conductor of 3 phases. 4 wire a.c. electrical system and the middle conductor of two phase, 3 wire system should be earthed by not less than two separate and distinct connections with earth at the generating station and at the sub-station.
ii) Metal frame of generators motors and other metallic parts of the equipment.
iii) All metal parts of electrical installation such as metal conduits, light fittings, iron clad main switches, iron clad distribution boards, cable sheathes etc.
iv) Earth pin of the three pin lighting and power plug sockets.
v) Steel tower, tubular poles, rail poles, etc. used in overhead transmission line should be earthed.
vi) Stay wires provided for overhead lines.