In transmission systems, a control character (a) that is used to accomplish media-fill stuffing or a time-fill stuffing in storage device or in a data transmission line and (b) that may be inserted and removed from a series of characters without affecting the meaning of the series. Note: The null character may affect the control of equipment or the format of messages. [ From Weik '89 ]
NULL CHARACTER (NUL)
Meaning of NULL CHARACTER (NUL) in English
Telecommunication standard terms English vocab. Английский словарь стандартных телекоммуникационных терминов. 2012