AT&T MERLIN Attendant for MERLIN LEGEND Installer's Manual page 47

Programming Features of MERLIN Attendant
If the customer wants callers to have the option to enter individual extension
numbers so that they can be connected to employees' telephones directly,
these commands can improve the processing of those calls. Call transfers to
extensions can be expedited when the MERLIN Attendant knows which
extensions are valid in the MERLIN LEGEND system and what the maximum
number of digits are in an extension (two to four). For example, if the customer
has only 2-digit extension numbers ranging from 10 to 55, once a caller enters
two numbers, the MERLIN Attendant quickly determines if the extension
number is valid and transfers the call without waiting for further input from the
caller.
NOTE:
Occasionally, a MERLIN LEGEND system has extension numbers with various
numbers of digits. For example, a system may include two-digit extension
numbers, such as 29, and four-digit extension numbers, such as 2489. In
systems with mixed numbers of extension digits, the "Extension Digits" Call
Processing option must be set to 19. The "Lowest Extension" and "Highest
Extension" option cannot be used when "Extension Digits" is set to 19.
Refer to Planning Form H and the programming instructions following the table
to change any of the values listed.
Changing Call Processing Options
2-15