 Syndicated programs from World War II and later years have nearly all survived.The survival of network programming from this time frame is more inconsistent; the networks started prerecording their formerly live shows on magnetic tape for subsequent network broadcast, but did not physically distribute copies, and the expensive tapes, unlike electrical transcription ("ET") discs, could be "wiped" and re-used (especially since, in the age of emerging trends such as television and music radio, such recordings were believed to have virtually no rerun or resale value).Thus, while some prime time network radio series from this era exist in full or almost in full, especially the most famous and longest-lived of them, less prominent or shorter-lived series (such as serials) may have only a handful of extant episodes.