Issues spotted by James Sutton.
Just going through WD-11 and I've spotted a few small inconsistencies in the table of return codes (2.2.2 pg.22):
16 - 0x10 - No matching subscribers (PUBACK) missing from table in 2.2.2
155 - 0x9B - QoS not supported, inconsistent with DISCONNECT table 18.104.22.168
148 - 0x94 - Topic Alias invalid (DISCONNECT) missing from table in 2.2.2
160 - 0xA0 - Maximum Connect time (DISCONNECT) missing from table in 2.2.2