More than one masking indicator (&2,&3) defined for &1!

What causes this issue?

More than one masking symbol has been defined for info structure &V1&.
However only one symbol is permitted (apart from a blank character).
Symbol &V3& is filled in the other entries.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Instead of '&V2&', enter the symbol '&V3' or the blank character.
If the blank symbol is entered, then no collective product allocations
are used for this product allocation step (even if they are entered in
the planning hierarchy).

Error message extract from SAP system. Copyright SAP SE.