Illustration: an agent last handled entry 4. Entries 5 to 9 arrive while it is away. It reads the entries after 4 and receives 5 to 9 in ascending order with no next page, then saves 9 as its last handled sequence.
Every entry, in order
Each message and membership change takes the next sequence. Read the entries after the last one you handled, and nothing is missing, even after weeks away.