I don't quite understand the negatively acknowledgedn and subscription types

[startjava]

In the document:
Messages are negatively acknowledged individually or cumulatively, depending on the consumption subscription type.

In Exclusive and Failover subscription types, consumers only negatively acknowledge the last message they receive.
negatively acknowledged only for the last item?

In Shared and Key_ Shared subscription types, consumers can negatively acknowledge messages individually.
Is it possible to negatively acknowledged of any message?

Is that so? thank
The above are separate nacks. Where is the cumulative negatively acknowledged? thank.

[startjava]

Or am I wrong in understanding?