[Requires free registration.
( ( -LSB- Requires ) ( ( free registration ) . ) )
(ROOT (S (NP (NNP -LSB-) (NNP Requires)) (VP (VBP free) (NP (NN registration))) (. .)))
Registration is only one of the requirements. 
( Registration ( ( is ( ( only one ) ( of ( the requirements ) ) ) ) . ) )
(ROOT (S (NP (NNP Registration)) (VP (VBZ is) (NP (NP (QP (RB only) (CD one))) (PP (IN of) (NP (DT the) (NNS requirements))))) (. .)))