AT&T Merlin Legend MLX-20L Operation Manual page 21

Covers
Removable plastic covers to protect
designation cards. The top cover protects
the 50 DSS button labels, and the lower
cover fits over the 10 fixed feature button
labels. Replace with textured side facing
you.
DSS designation cards
Cards for labeling the extensions and
features assigned to each button
DSS buttons
50 buttons used to direct or make calls to
co-workers
Fixed buttons
10 additional buttons, including
Message Status and 3 Page buttons. The 6
remaining buttons on the first DSS are
unusable. If a second DSS is connected to
the console, the 10 buttons at the bottom of
the second DSS are unusable.
Fixed Message Status button
A button used with the Page buttons to
see which phones have message lights
on
Fixed Page buttons
3 buttons used to select the range of
extensions the DSS buttons represent
1-7