In §11.1, flags 2 bit 2 is documented as being for version 6, but it should be version 4 and above.
First, Infocom's EZIP spec (corresponding to V4) says bit 2 is "request for status line refresh (set by EZIP only)", while the V3 ZIP spec simply says that bit 2 is reserved; so Infocom added it in V4.
More importantly, this is actually used by one V4 game (maybe more, but I couldn't find any). In A Mind Forever Voyaging (77-850814):
In §11.1, flags 2 bit 2 is documented as being for version 6, but it should be version 4 and above.
First, Infocom's EZIP spec (corresponding to V4) says bit 2 is "request for status line refresh (set by EZIP only)", while the V3 ZIP spec simply says that bit 2 is reserved; so Infocom added it in V4.
More importantly, this is actually used by one V4 game (maybe more, but I couldn't find any). In A Mind Forever Voyaging (77-850814):
Corresponding to the AMFV ZIL source (in parser.zil):