From 1 January 2008 a new rule of golf has been introduced that limits the spring-like effect of drivers for players at all levels.
To help clarify the question of conformity of driver clubfaces, R&A Rules Limited has compiled and published two lists:
The List of Conforming Driver Heads may be accessed by clicking here: all driver heads sold before 1 January 1999 are considered compliant with the limitation on the spring-like effect and so are automatically included in this list.
The Non-Conforming Driver List may be accessed by clicking here.