A structure defined by the SW01SR
DSECT that contains the displacement and length of logical record (LREC) key
fields, a comparison operator, and values to compare the fields
against. The key list is used to locate records that match the
specified criteria. A key list provides the same function as the
KEYn parameters. However, only key lists can be used for
default keys on read operations, Boolean operators with keys, and global
modification of LRECs. See also default-key key list,
modification key list, selection key list, and
sort/merge key list.