Relaxed the business rules to allow inclusion of receipt requests even to the bare JID and even if the sender does not yet know whether the intended recipient supports this protocol; clarified the level of reliability that this protocol does and does not provide; provided explicit recommendations about when and when not to request receipts; removed text about XEP-0155 negotiation.
Clarified the level of reliability that this protocol does and, most importantly, does not provide; explicitly discouraged dependence on receipts unless some other protocol is used to negotiate the use of message receipts; provided explicit recommendations about when and when not to request receipts; relaxed the business rules to allow inclusion of receipt requests even to the bare JID and even if the sender does not yet know whether the intended recipient supports this protocol; removed text about XEP-0155 negotiation.