ents, this method will be compli- cated for end-users. Fax Libraries that contain more than 10 to 15 documents are likely to be awkward to support when using audio menus. Too many choices in a menu, 190 28 The Telecom Handbook CHAPTER 9 or menus nested deeper than three levels, may confuse and irritate callers. Heavy Maintenance. If the Fax Library is changed of- ten, this method requires a large amount of maintenance. New audio greetings and call processor definitions need to be created each time changes are made. Document Numbers The most common way to support a Fax Library is through the use of document numbers. Using this method, the Fax-on- Demand system prompts the caller to enter the index number of the document he wishes to receive. The typical call scenario is as follows: Caller picks up the telephone and dials the Fax Server access number. "Thank you for calling DIgby 4 Group. If you know the extension of the person you are calling, you may dial it now. For tips on managing your telephone sys- tems and services, access our Fax Library by press- ing 7. " Caller presses 7. "If you are a first-time user of our Fax Library, press 1 to have an index of available material faxed to you. If you know the document number you wish to receive, you may enter it now." Caller presses 1. "Please make your selection from the following documents: For Dollar Saving Tips, select 11; For Tips on Purchasing a New Telephone System, se- lect 12; For Tips on Training Your Switchboard The Telecom Handbook & 191 FAX SERVERS Operators, select 14; For Tips on Purchasing Local and Long Distance Service, select 15.; For Tips on Maintenance Agreement Negotiation, select 16; For Telephone Bill Management Tips, select 17." Caller presses 16, the index number of the document re- quested. "Please enter the telephone number of your fax ma- chine, followed by a pound sign." Caller enters the telephone number of the fax machine where they wish to have the fax sent, followed by a pound sign. "The number you entered was [System repeats the ent