The prefix information contains the two-byte field at the beginning that specifies the length of the used data area of this record. The third byte is the statement type. Other prefix information relates specifically to the type of JCL statement (such as, "account number required" on a JOB statement or "SYSOUT data set" on a DD statement). The text string for a JOB statement contains seven bytes of prefix information; all other JCL statements have a prefix section containing five bytes.