Need quick answer to: What is prepend option?

[Snoopy572]

On the phones dealing with numbers, what does it mean when it gives you the option to prepend?

[Snoopy572]

On the phones dealing with numbers, what does it mean when it gives you the option to prepend?
Nevermind found this:
Prepend dialing allows you to alter a phone number in your Phone Book by adding additional number. For example, if your Internal Phone Book entry was entered without an area code and you are out of town, you can prepend that entry with the appropriate area code. Another example would be if you wanted to make a phone call using a calling card. You would prepend the calling card number before the phone number of the person you want to call.