Why does the NEC Retroactive itself

[brother]

I think this was brought up before, but its not too often you see it in the NEC. Why is it the NEC has made it self 'retroactive' required for luminaires in existing installations for pools??
Is this 'adopted' in other areas. Im referring to NEC 2008 680.22(C)(3)

 

[Cavie]

Why is it the NEC has made it self 'retroactive' required for luminaires in existing installations for pools??

To save lives??? This is nequired to be done during a remodel. There will be no code cops going around and looking for violaters.

 

[don_resqcapt19]

I don't see that as a retroactive requirement. I see it as a requirement that applies to a fixture that is in place when a new pool is constructed.