Wiping
Wiping, also known as junking, is a colloquial term for action taken by radio and television production and broadcasting companies, in which old audiotapes, videotapes, and telerecordings (kinescopes), are erased, reused, or destroyed. Although the practice was once very common, especially in the 1960s and 1970s, wiping is now practiced much less frequently. Older video and audio formats took up much more storage space than modern digital video or audio files, making their retention more costly, thus increasing the incentive of discarding existing broadcast material to recover storage space for newer programmes.