Question: what is the meaning of schedule in pipes
[{'answer': 'wall thickness', 'provenance': [{'wikipedia_id': '4015299', 'title': 'Nominal Pipe Size', 'start_paragraph_id': 1, 'start_character': 460, 'end_paragraph_id': 1, 'end_character': 474, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4015299', 'title': 'Nominal Pipe Size', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1004, 'bleu_score': 0.834094036449009, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 766827172617357377}, 'section': 'Section::::Abstract.'}]}]