Section 23 Relief

I have outlined a position below where one has a rental property with s23 relief and also capital allowances. Which relief has to be claimed first?

Obviously the second example is more beneficial.

Rental Income €100,000
Capital Allowances 40,000
Rental profit 60,000
Less S23 relief 500,000
Loss c/f 440,000

Rental Income €100,000
Less S23 relief 500,000
Rental profit NIL
Excess Capital Allowances 40,000 offset against other income

What are the nature of the "excess" capital allowances as most can not be off set against income other than Rental Income (Case V).