Specifies the length, in bytes, of the keys used in the data
set.
The number of bytes is:
0 to 255 for non-VSAM data sets. The key length must be less than
or equal to the record length.
Note: Use only 0 for a member
of a partitioned data set extended (PDSE). Use 0 or 8 to perform input
operations on the directory of a PDSE.
1 to 255 for VSAM key-sequenced (RECORG=KS) data sets. A key length
must be specified, either explicitly with the KEYLEN or LIKE parameter,
or in the data class for the data set. The key length must be less
than the record length.