Resource name limitations for files and DDNAMES
To conform to z/OS conventions, the IBM Transformation Extender truncates file and resource names to 8 characters when a map is executed.
Therefore, resource names and their values have an 8-character limitation. Because this includes the percent (%) symbols that enclose the resource name when using it in a source or target resource, the resource name must not be longer than 6 characters. For example, the resource name MyFile is specified as %MyFile% when used in the Command setting of an input or output card.
The resolved resource value is actually a DDNAME that is defined on the z/OS Batch platform. The resolved value must conform to the rules for DDNAMES.
See "DDNAMES" for more information about defining DDNAMES for resolved resource values.