(S (S (S (BASENP (NN Health) (NNS warnings)) (VP (MD must) (VP (VB occupy) (NP (NP (QP (ADVP (IN at) (JJS least)) (NN half))) (PP (IN of) (NP (BASENP (DT the) (JJ principal) (NN display) (NNS areas)) (PP (IN of) (BASENP (DT a) (NN pack))))))))) (CONJP (COMMA ,) (CC but)) (S (BASENP (PRP they)) (VP (VP (MD must) (RB not)) (VP (VB be) (NP (QP (ADVP (RBR less) (IN than)) (NN 30)) (NN %)))))) (PERIOD .))