MQ Series call (MQINQ) syntax


Our AcuCobol system interfaces with Mq Series successfully and we utilise calls such as MQCONN, MQOPEN and MQGET which are well documented and work well. For the first time I am trying to use the MQINQ call but can't find an example in the documentation or anywhere else. Can anyone give an example of this call being called using AcuCobol? 

What I'm really interested in is for what parameters I need to use 'BY REFERENCE' and which ones I need to use 'BY VALUE'.