WorK Book (WKB)

b10b16fieldtypesizebitfieldcomments
00fnshort   
22grfwkbuns short   
44lvlshort   
66fnptshort:4000F 
  fnpdshort:12FFF0 
88doclong  unused

cbWKB (count of bytes of WKB) is 12 (decimal), C (hex).