AT&T MERLIN LEGEND System Reference Manual page 397

Features
System Programming
Specify whether outgoing calls only or both incoming and outgoing calls are
recorded. The factory setting is for both.
Options -> SMDR -> Call Report
Specify the duration of the call before SMDR begins to record information.
The factory setting of 40 seconds can be changed to 0-255 seconds.
Options -> SMDF -> Call Length
Select the report format-basic (the factory setting) or ISDN.
Options -> SMDR -> Format
Related Features
Forced Account Code Entry
Account Code Entry
2-348 Station Message Detail Recording