The two documents attached below discuss BS 8436 

The first relates to amendment No 2, 2004 to BS 7671: 2001 which includes changes concerning cables concealed in a wall or partition at a depth of 50mm or less from the surface.  Regulation 522-06-06 is amended and Regulation 522-06-07 is deleted.

The second document is extracted from the NICEIC Technical Manual and includes:

1. Rules for protection of cables against penetration
2. Cables enclosed in hollow metal sections of partitions
3. Protection against damage during construction works
4. Locations containing a bath or shower