对于EDGAR提交类型的表格8-K:报告的日期, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.
Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, 可选后缀可能包含1-4个字符, and the fields are separated with a hyphen.