a) The specific signal configuration, reference pulses, voltage levels, etc., that describe the input/output requirements for a particular tape of equipment. Some standards have been established by professional groups or government bodies (such as SMPTE or EBU). Others are determined by equipment vendors and/or users. b) A set of rules or characteristics defining a particular television system. Some standards (such as those contained in FCC rules and regulations) are mandatory. Most (including those of the EIA, IEEE, and SMPTE) are voluntary. The establishment of a standard often freezes development at a certain level but allows users and manufacturers to deal with a much larger array of products than might be available without a standard. There is currently one U.S. HDEP standard, the ATSC/SMPTE 1125 scanning-line system. CCIR system E is an HDTV transmission standard, used in France, calling for 819 scanning lines in a 14 MHz bandwidth.