Characteristics required in the existing allocation

To be used to satisfy your request, the data set that is the existing allocation must have the following properties:

It must not be in use.
It must not be a member of a concatenated group.
It must have the same volume serial number as any explicitly specified in the request.
It must have the permanently allocated attribute, if its disposition is DELETE and the request specifies a status of MOD.
It must not be a generation data group data set.
It must not be a z/OS® UNIX file.
It must either have the convertible attribute (described in Convertible attribute) or, if the request is in a form other than “&dsname”, all of the following must be true:
- The request does not specify a ddname; or the specified ddname matches the ddname associated with the existing allocation. A terminal request that does not specify a ddname cannot be satisfied by an existing allocation that does not have the convertible attribute.
- For partitioned data sets, the member name specified in the request is the same as the member name associated with the existing allocation; or a member name is neither specified in the request nor associated with the existing allocation.
- The request does not specify input only, output only, or any DCB parameters.
- If the request specifies a status of MOD, MOD is also associated with the existing allocation; or it is neither specified in the request nor associated with the existing allocation.
- The request does not specify that the convertible attribute be assigned to the allocation.
- The request does not specify that only existing allocations with the convertible attribute may be used.

If the request specifies dsname in the form “&dsname”, the request does not specify a ddname; or the specified ddname matches the ddname associated with the existing allocation. A terminal request that does not specify a ddname cannot be satisfied by an existing allocation that does not have the convertible attribute.