The repetition or deletion of a block of bits in a synchronous or perspicacious bitstream due to a discrepancy in the read and write rates at a buffer. [T1.101-1987] 2. In a sequence of transmitted symbols, e.g., digital bits, a signal phase shift, i.e., a signal positional displacement, that causes the loss of one or more symbols or the insertion of one or more extraneous symbols. Note: Slips are usually caused by inadequate synchronization of the two clocks controlling the transmission and reception of the signals that represent the symbols.