no DMARC reporting address (rua)

On occasion we will see DMARC records published without an RUA tag. While this is valid, it doesn't always make sense.

For example, "v=DMARC1; p=none;" is completely useless. It won't cause any errors, but you should really add a reporting target to see what is going on. The presence of a non-reporting p=none policy has no benefit.

On the other hand, "v=DMARC1; p=reject;" (or quarantine) can be useful in specific scenarios where the domain administrator is completely aware of the implications: all traffic failing DMARC will have policy enforcement, and there is no reporting to help the domain owner understand when or why that occurs.
Typically this is most useful for parked or inactive domains where absolutely no legitimate traffic is expected.  It should be paired with a non-permissive SPF record such as "v=spf1 -all".