[MQTT]: Retain true for properties

[egekorkan]

For a topic that Exposed Thing publishes to, what does it mean to have to retain flag information in the forms?
Let's say we have the following form for a property:

{
  "href": "mqtt://example.com/example/light/currentswitch",
  "op": ["observeproperty"],
  "mqv:controlPacketValue": "SUBSCRIBE",
  "mqv:options": [ { "mqv:optionName": "retain", "mqv:optionValue": 1 }]
}

So this should mean that an MQTT subscriber should subscribe to this topic in order to observe a property. Should the subscriber ignore the last line since it is not something it should do, i.e. the publisher publishes with retain flag set to true so that the last value of the property is in the topic. OR can the publisher use this last line to give a hint that it publishes with retain set to true, so the subscriber should understand that it will get the last value of the property upon subscription, i.e. do a readproperty.
My answer would be that if the publisher publishes with retain set to true, there should not be this line and there must a readproperty op value. Thus, there would be some information (publisher publishing with retain set to true) not visible in the TD. This also implies a change to the editor's draft.