Nesting 'And' 'or' within an If

[SSharrock]

Good Afternoon,

On the attached sheet in column X, I am trying to input the Allocation percentage dependent on a number of variables:

Type (Bar, Blank, Coil, Sheet, Special)
Sub Fam Code (2A02, BC02-05, BC99, BZ99)
Sup Category (Arcelor, Independent, Tata/ Corus)

The allocation percentage is based on the below; anything outside of this should result in "Other".
Sheet (BC02/03/04) A=40%, T=40% & I=20%
Coil (BC02 & BC03) A=40%, T=40% & I=20%
Coil (BC04) A=30%, T=50% & I=20%

Example 1:
Type - Sheet & Coil
Sup Category - Independent
Result 20%

Example 2:
Type - Coil
Sup Category - Tata/ Corus
Sub Fam Code - BC04
Result 50%

Example 3:
Type - Coil
Sup Category - Arcelor
Sub Fam Code - BC04
Result 30%

I hope I have made it clear as to what I intend to change.