“`
?OBKRUO
XOGHULB
SOLIFBB
WFLRVQQ .EASTNO
PRNGKSS RTHEAST
OTWTQSJ
QSSEKZZ
WATJKLU
DIAWINF
BNYPVTT .BERLIN
MZFPKWG CLOCK..
DKZXTJC
DIGKUHU
AUEKCAR
“`
With both BERLINCLOCK and EASTNORTHEAST, I think he’s really trying to point out all those doubles with a period of seven (the same number of letters as in KRYPTOS, the key).
So… some sort of block or transposition (bifid?) on top of whatever’s reducing the IOC (fractionation, beaufort…).
I like “–IDBYROWS” as a masked hint, “BIFID BY ROWS” or “TRIFID BY ROWS” (but Sanborn claims IDBYROWS is not really in play anymore, so I’m probably just seeing things).
