Then I am confused by these statements:
First from Jeff Lindborg:
Just as a side note here - Unity 4.2(1) has an ES available that provides new functionality on call handlers that can automate this to a great degree - this will also be in the upcoming Unity 5.0(1) release currently in EFT as well, of course.
The short story is you can create a call handler that automatically appends or pre pends (or both I guess, though I can't imagine why you'd need that) digits that you dial while listening to a greeting in that call handler.
So for instance if you create a call handler called "Prefix 365" and callers listening to the greeting in that handler dials 1234 the actual database lookup for a match is 3651234 - if that fails then it looks up just 1234 and only if THAT fails do you get the "I'm sorry..." prompt.
This means you no longer have to tell folks to prepend digits in the greeting as you describe above.
This is only there when you apply ES 8 to 4.2(1) and you have to use bulk edit to change the prefix/postfix digits on the handlers in question since it's not exposed in the SA - however I believe it's a step in the right direction for this particular issue.
Also be aware that applying ES8 will require you rerun the failover wizard if the server is part of a primary/secondary failover pair.
And Second from the release notes for ES132:
CSCse16249
Pre-pend and/or post-pend digits can now be defined for any call handler or subscriber. If pre-pend and/or post-pend digits are defined for a subscriber or call handler, the digits will be pre-pended and/or post-pended to any extension that a caller may dial while listening to the greeting for the call handler or subscriber. The modified extension is then used for searching, ensuring that Unity takes the appropriate action. For example, if a call handler named "Sales" has pre-pend digits configured as "123" and post-pend digits configured as "456", and if a caller dials extension "1000" while listening to the greeting for call handler "Sales", Unity will first search for extension "1231000456," and if found will route the call appropriately. If no match for "1231000456" is found, then Unity will search for the originally dialed extension ("1000", in this case). Thus, the customer can set up multiple call handlers where the caller is able to enter the same digits (for example "1000") to reach a support person, but the calls can actually be routed to a support person appropriate to the particular call handler (for example, a "Tech Support" call handler or a "Sales" call handler), due to the presence of unique pre- and post-pended digits.
Note that the use of pre-pend or post-pend digits does not simulate digits dialed by the caller. For instance, configuring "#2" as post-pend digits for a call handler will not invoke the transfer override function for extensions dialed from that call handler. Assuming such a configuration, if a caller dialed "123" from the call handler, Unity would look for extension "123#2" and fail to find a match. Using pre-pend or post-pend digits can simulate abbreviated dialing within Unity on a per-call handler or subscriber basis. The configuration for pre-pend and post-pend digits applies for the duration of the greeting of the call handler or subscriber for which they are configured. Pre-pend and post-pend digits cannot be applied to a directory handler and do not apply to message addressing.
