Use SYSLIB DD statements if your program contains COPY or BASIS statements. These DD statements define the libraries (partitioned data sets) that contain the data requested by COPY statements in the source code or by BASIS statements in the input stream.
//SYSLIB DD DSNAME=copylibname,DISP=SHR
Concatenate multiple DD statements if you have multiple copy or basis libraries:
//SYSLIB DD DSNAME=PROJECT.USERLIB,DISP=SHR // DD DSNAME=SYSTEM.COPYX,DISP=SHR
Libraries are on direct-access storage devices. They cannot be in the HFS when you compile with JCL or under TSO.
You do not need the SYSLIB DD statement if the NOLIB option is in effect.