If I wanted to import a customer's list of 300 speed dials to a tda50, in what format should they send it to me?

CSV files.. Comma Separated Values
2.5.8 maint console book.

Feature - Speed Dial and Caller ID
Data Type /Import Destination
System Speed Dialing Number / Location
Name / Name
CO Line Access Number
+Telephone Number / Dial
CLI Destination / CLI Destination

Export Outlook contacts to CSV file:

https://email.about.com/od/outlooktips/qt/Export_Outlook_Contacts_to_CSV.htm

Thanks alot