StartWithLastReceived : Clarification

[rampratapa]

// Subscribe starting with most recently published value
var opts = StanSubscriptionOptions.GetDefaultOptions();
opts.StartWithLastReceived();
var s = c.Subscribe("foo", opts, (obj, args) =>
{
    Console.WriteLine("Received a message: {0}",
        System.Text.Encoding.UTF8.GetString(args.Message.Data));
});

I have question about the above StartWithLastReceived flag. What is really it is doing

• Case 1 : The messages are published and subscribers are down. For example publisher publishes 1 to 10 messages. the subscriber is up at message 9, if the above property is set then it start receiving from 9 and 10 and ignore previous ones or it receives messages from 1 through 10.

• Case 2: if the publisher publishes 1 to 20, the subscribers down randomly and it is a durable subscribers case and if we set the above property, do we receive all messages or did we loose messages.

Another question, what is the default behavior.

Thank you for your help.

Thanks
ram