The Free On-line Dictionary of Computing (30 December 2018):
Basic Encoding Rules
ISO 8825
ITU X.209
X.209
    (BER) ASN.1 encoding rules for
   producing self-identifying and self-delimiting transfer
   syntax for data structures described in ASN.1 notations.
   BER is an self-identifying and self-delimiting encoding
   scheme, which means that each data value can be identified,
   extracted and decoded individually.
   Huw Rogers once described BER as "a triumph of bloated theory
   over clean implementation".  He also criticises it as designed
   around bitstreams with arbitrary boundaries between data which
   can only be determined at a high level.
   Documents: ITU-T X.690, ISO 8825-1.
   See also CER, DER, PER.
   (1998-05-28)