maximum transaction retention property ?

1)Have Transactional replication and wanted to know what was the maximum
transaction retention property for distribution database is
2Also i was looking at the properties and it says that the subscription
could expire or get dropped if not synchronised within 72 hours. So my
question here is under what condition would it expire and when would it get
dropped
Thanks
Please see my reply to your other post.
Rgds,
Paul Ibison SQL Server MVP, www.replicationanswers.com
(recommended sql server 2000 replication book:
http://www.nwsu.com/0974973602p.html)