What is the fail_reads.bam file?

On the Revio platform, for each hifi_reads.bam there is one fail_reads.bam file. This file contains one representative read per ZMW. The ff tag encodes why each read ended up in this file:

Flag	Description
0x1	CCS reads with predicted accuracy below QV 20.
0x2	Control CCS reads.
0x4	Single-stranded CCS reads.
0x8	The median full-length subread from molecules that do not produce a CCS read but have at least one full pass.
0x10	CCS reads which are a concatenation of the adapter, with possible short non-adapter sequence in between.
0x20	CCS reads with miscalled adapter which is enclosed by a sequence and its reverse complement, either spanning to the end.
0x40	CCS reads that have one or more adapters close to either end.