Ēš Hold Preference determines either Exclusive hold or System hold as
the preferred hold state and is activated on the first depression of
the [HOLD] button.

To activate the Hold,

Ēš Press HOLD button, connected call placed in the preferred hold state.

To access a call from Hold,

Ēš Lift the handset or press the SPEAKER button.
Ēš Press the CO/IP line button or dial 8# and the CO/IP line number.