The 0 refers to the very first item in that nested record, and that is "Alice". As it is possible to see, it is possible to obtain items from the nested lists by implementing a number of indexing operations inside of a row. This technique is extensible to lists with https://rafaelekpwb.wikinstructions.com/843271/how_much_you_need_to_expect_you_ll_pay_for_a_good_dosierung