[JDEV] PubSub Subscription Requests

[Stephen Pendleton]

I am doing some work on the client side with pubsub and I have a question
about the subscription approval request that gets sent to a potential
subscriber to a node. The JEP states this:

When a Jabber entity wishes to subscribe to a node, it sends an IQ request
to the pubsub service. Depending on the configuration of the node, several
things may happen. If the node has "open" subscriptions, the potential
subscriber receives either a result or an error. If the node has been
configured so that subscription requests must be approved by the node owner
(or a designated approver), the pubsub system sends a message with a
jabber:x:data form to the node owner requesting authorization. The node
owner may approve the subscription request by sending back a jabber:x:data
submit. To deny the request, the owner must send back a jabber:x:data cancel
message to the pubsub service

Now my question/comment is, is this the best way to do this? What is the
advantange of sending a jabber:x:data form? Will there be implementations
that require jabber:x:data data to be sent back? The only reason I ask this
is because it seems to me it is pretty much the same as a simple "roster
subscription request" that would require only a simple yes/no response sent
back.

Thanks!