C:\Users\matt>fastboot oem unlock 0000775000000000000000000000001200464475200611
2
...
(bootloader) fastboot oem unlock [ unlock code ]
OKAY [  0.112s]
finished. total time: 0.115s

C:\Users\matt>fastboot oem unlock 0000775
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.397s

C:\Users\matt>fastboot oem unlock 012345
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.396s

C:\Users\matt>fastboot oem unlock 0123456
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.397s

C:\Users\matt>fastboot oem unlock 01234567
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.397s

C:\Users\matt>fastboot oem unlock 012345678
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.398s

C:\Users\matt>fastboot oem unlock 0123456789
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.397s

C:\Users\matt>fastboot oem unlock 01234567891
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.399s

C:\Users\matt>fastboot oem unlock 012345678912
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.398s

C:\Users\matt>fastboot oem unlock 0123456789123
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.397s

C:\Users\matt>fastboot oem unlock 01234567891234
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.399s

C:\Users\matt>fastboot oem unlock 012345678912345
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.398s

C:\Users\matt>fastboot oem unlock 0123456789123456
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.399s

C:\Users\matt>fastboot oem unlock 01234567891234567
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.399s

C:\Users\matt>fastboot oem unlock 012345678912345678
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.400s

C:\Users\matt>fastboot oem unlock 0123456789123456789
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.400s

C:\Users\matt>fastboot oem unlock 01234567891234567891
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.400s

C:\Users\matt>fastboot oem unlock 01234567891234567891
...
(bootloader) Password incorrect!
(bootloader) OEM unlock failure!
FAILED (remote failure)
finished. total time: 0.400s

#
#
#It appears that anything between 0 and 20 digits long will show failure, anything above not accepted.
#
#

C:\Users\matt>fastboot oem unlock 012345678912345678912
...
(bootloader) fastboot oem unlock [ unlock code ]
OKAY [  0.108s]
finished. total time: 0.110s

C:\Users\matt>fastboot oem unlock 0123456789123456789123
...
(bootloader) fastboot oem unlock [ unlock code ]
OKAY [  0.108s]
finished. total time: 0.111s

C:\Users\matt>