Hallo Kaym,
im Memorandum to User für R520 steht folgendes:

2d.xi) ALCOBJ and DLCOBJ lock space scope

The Allocate Object (ALCOBJ) command and Deallocate Object (DLCOBJ)
command have an additional SCOPE parameter value of *LCKSPC. The new
parameter scopes locks to the lock space when a lock space is attached
to the current thread. If no lock space is attached to the thread, the
lock will be scoped to the job. A lock space is an internal system
object that can own object and record locks, and can contain other
internal system objects.

In V5R2, some products such as WebSphere(R) licensed programs use the
new lock space support. If you have user exits for these products that
use ALCOBJ and DLCOBJ and experience lock conflicts, you may need to
change the SCOPE parameter to *LCKSPC.

In general, this change will not affect most existing applications.
Only applications that use the XA and JTA APIs for transaction
management have a potential to be impacted. The likelihood for a
failure to occur would be if a stored procedure or trigger program
attempted to use ALCOBJ on a database file and that file was already
locked by a lock space.

Gruss TARASIK