From Mysteriorum Liber Tertius, April 28, 1582. "They are proper to every King and prince in theyre order."
A version of the Ensigns was published in Pat Zalewski's Golden Dawn Enochian Magick which shows all the lowercase letter "B"s in the Ensigns as numeral sixes. This version is a fairly recent invention, first appearing in print in the 1960's.
An much older version created by the pseudonymous "Dr. Rudd" shows the names of various traditional demons written on the Ensigns. Rudd's notion was that the letters stood for the names of these demons, and the number of times the letter appeared signified the number of times the demon was to be invoked.
Neither of these versions, nor Dr. Rudd's notion, has any justification in the diaries.
The versions shown below were prepared from scans of the diaries, cleaned up to remove the dirt and smudging from four centuries of aging. It can be seen that the characters "b" and "6" are quite distinct.
(Images courtesy of Clay Holden and the John Dee Publication Project.)
The Ensign of Venus
The Ensign of Sol
The Ensign of Mars
The Ensign of Jupiter
The Ensign of Mercury
The Ensign of Saturn
The Ensign of Luna