What are the entries in a bookmark store file?

The AMPS clients each use a similar format for the fully-logged bookmark store.

There are three types of entries in the file:

Entry	Description
b	Bookmark for a message received by a subscription
d	Discard for a bookmark
p	Bookmark for the last message persisted in the local transaction log (returned in persisted ack)

When an AMPS client has a bookmark store, the AMPS client automatically requests persisted acknowledgements for a bookmark subscription. These acknowledgements keep track of the last point to which AMPS has processed messages for the subscription: even if a subscription has not received messages for a period of time, this acknowledgement helps to efficiently resume the subscription at the correct point.