Well, the point in serial numbers is to make a checklist by product, so you've got a mistake there. The actual list should be:
Smith/#11 Limited = BCS01L
Smith/#11 Signature = BCS01S
Amy Pond Limited = BCS02L
Amy Pond Signature = BCS02S
Any Pond Alternative Head Sculpt = BCS02E
Tennant/#10 Limited = BCS03L
Tennant/#10 Signature = BCS03S
Tennant/#10 50th LE = BCS03E
Baker/#4 Limited = BCS04L
Baker/#4 Signature = BCS04S
BC/Holmes Limited = BCS05L
BC/Holmes Signature = BCS05S
MF/Watson Limited = BCS06L
MF/Watson Signature = BCS06S
WH/#1 Limited = BCS07L
WH/#1 Special = BCS07S
Tennant/Dynamix = BCSD01
Tennant/Dynamix 50th LE = BCSD01E
And since some companies don't seem to number exclusives, it'd be:
Smith/#11 Limited = BCS01L
Smith/#11 Signature = BCS01S
Amy Pond Limited = BCS02L
Amy Pond Signature = BCS02S
Any Pond Alternative Head Sculpt = BCS02E
Tennant/#10 Limited = BCS03L
Tennant/#10 Signature = BCS03S
Baker/#4 Limited = BCS04L
Baker/#4 Signature = BCS04S
BC/Holmes Limited = BCS05L
BC/Holmes Signature = BCS05S
MF/Watson Limited = BCS06L
MF/Watson Signature = BCS06S
WH/#1 Limited = BCS07L
WH/#1 Special = BCS07S
Tennant/Dynamix = BCSD01
Tennant/#10 50th LE = Anniversary Exclusive
Tennant/Dynamix 50th LE = Anniversary Exclusive
And the Pond head isn't an exclusive (which is labeled with E) nor will it have a number so it'd be:
Smith/#11 Limited = BCS01L
Smith/#11 Signature = BCS01S
Amy Pond Limited = BCS02L
Amy Pond Signature = BCS02S
Any Pond Alternative Head Sculpt = BCS02E
Tennant/#10 Limited = BCS03L
Tennant/#10 Signature = BCS03S
Baker/#4 Limited = BCS04L
Baker/#4 Signature = BCS04S
BC/Holmes Limited = BCS05L
BC/Holmes Signature = BCS05S
MF/Watson Limited = BCS06L
MF/Watson Signature = BCS06S
WH/#1 Limited = BCS07L
WH/#1 Special = BCS07S
Tennant/Dynamix = BCSD01
Tennant/#10 50th LE = Anniversary Exclusive
Tennant/Dynamix 50th LE = Anniversary Exclusive
Amy Pond Alternative Head Sculpt = xxxxxx