one more question regarding emergency & priority

Hi,

According to the ABNF, it's possible to set both emergency and priority
context attributes in an action request.

For example:

Transaction = 202 {
    Context = 5 { 
       Emergency,
       Priority = 4,
        Modify = ip/10/if3/2 {
        ...

What is the meaning of such a command? Is it only semantically
permitted, but not practically used? Am I missing something?

Many thanks,
Miri