A (waiting period) can be customary.Logical formLearned from73 sentences. Norms can be customary.Logical formLearned from71 sentences. A method can be customary.Logical formLearned from71 sentences. Regulatory approvals can be customary.Logical formLearned from68 sentences. A level can be customary.Logical formLearned from65 sentences. An international humanitarian law can be customary.Logical formLearned from63 sentences. A charge can be customary.Logical formLearned from63 sentences. Duties can be customary.Logical formLearned from63 sentences. Fees can be customary.Logical formLearned from62 sentences. A rule can be customary.Logical formLearned from59 sentences. A time can be customary.Logical formLearned from55 sentences. A response can be customary.Logical formLearned from54 sentences. A duty can be customary.Logical formLearned from53 sentences. Procedures can be customary.Logical formLearned from53 sentences. Marriages can be customary.Logical formLearned from52 sentences.