This is the level associated with the subscription. Publications are only delivered to this subscription if it is in the set of subscriptions with the highest SubLevel value less than or equal to the PubLevel used at publication time. However, if a publication has been retained, it is no longer available to subscribers at higher levels because it is republished at PubLevel 1.
The value must be in the range zero to 9. Zero is the lowest level.
The initial value of this field is 1.
For more information see Intercepting publications.
If altering an existing subscription using the MQSO_ALTER option, then the SubLevel cannot be changed.
Combining a SubLevel with a value greater than 1 with the option MQSO_PUBLICATIONS_ON_REQUEST is not allowed.
On return from an MQSUB call using MQSO_RESUME, this field is set to the current level being used for the subscription.