DALSYML lists the symbol names to be passed to JES when an internal
reader is allocated. 
This
key is allowed only when text unit DALSYSOU is also coded, and its
value must be the 6-character string INTRDR. This
is because it is meant for allocations to an internal reader only.
When you code this key, # contains the number of symbol names being specified up to a maximum of 128 (X'0080'), LEN is the length of the PARM, and PARM contains valid symbol names. In addition, '*' is a valid value for a symbol name to indicate that all symbols can be used in JCL; refer to the SYMLIST keyword in the DD statement in z/OS MVS JCL Reference.
Example: To specify SYMLIST with symbol name NAMES on a
DD, code:
KEY # LEN PARM
802B 0001 0005 D5 C1 D4 C5 E2
0018 0001 0001 5C
0019 0001 0006 C9 D5 E3 D9 C4 D9The DSNTYPE text unit key section has a format for
multiple text units.