Yeah, I noticed that it was omitted in the 12.1 Documentation as well so I think it may have been an oversight that was carried over into 12.2 doc since the process changed a bit. My guess is that the old documentation was just copied and pasted into the new doc as support for the old method.
EDIT: I found the SYNTAX. It helps to scroll upwards sometimes. It would have been nice if they had placed the syntax with the description like the other keywords though.
I also noticed that the space statements for CYLINDERS, TRACKS and BLOCKS has no syntax listed. Based on the other statements it would seem to be along the lines of CYLINDERS(cylinders) but again, not sure. Likewise the START and END statements specify the format of the date and time but not the syntax for the statement. The doc also mentions using the message number with the START/END statements but it offers no syntax so again, I can assume but we all know what that would get me.