Fixed rule deciding priority in a queue? (8,5)
I believe the answer is:
standing order
'fixed rule' is the definition.
'standing order' can be an answer for 'rule' (standing order is a kind of rule). I am unsure of the 'fixed' bit.
'deciding priority in a queue?' is the wordplay.
I cannot really understand how this works, but
'in' is within the answer.
'a' could be 'an' and 'an' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for standing order that I've seen before include "rise!" , "Regular way to pay" , "gets you on your feet!" , "Instruction for bank to make regular payments" , "Instruction to bank for payment at regular intervals" .)