AT&T MERLIN LEGEND Release 2.0 System Programming Manual page 778

Programming Special Characters
Single-Line Telephones
Some dialing sequences need special characters. For example, you would
press and release either the Recall or Flash button or the switchhook to insert a
pause in a dialing sequence after a dial-out code to allow the system to seize an
outside line before dialing the number.
Table G-1. Special Characters for Single-Line Telephones
Press...
Recall, Flash
or switchhook
#
G-2 Single-Line Telephones
Means...
Pause. Inserts 1.5 second pause in the dialing
sequence. Multiple consecutive pauses are
allowed.
End of Dialing. Used to signal the end of the
dialing sequence or to separate group digits,
e.g., account code from number dialed.