C2MS11 — Consider forcing a limited subscription

In the case of Mnemonic Value Request Message and Archive Mnemonic Value Request Message, the requestor can specify a STOP-TIME or DURATION, but both are optional. If neither is specified, the subscription is open-ended with no knowable end, until the requestor sends a 'STOP' message. In order to avoid infinite fulfillment of a subscription to a potentially lost requestor, we could enforce a concept that a requestor must specify either a STOP-TIME or Duration.

In practice, this is an inadequate requirement, since a caller could specify a very long duration, like 1000 years, and circumvent the desire of this issue.

However, this is issue simply captures the idea to promote further discussion.