Polycom VVXTM 1500 - Manual (Page 161)

Using the Advanced Features of Your Phone
4 - 7
The My Status screen displays.
2. Tap the status you want, and then tap the Select soft key.
This affects information sent to phones watching you. Presence
information will also be sent to watching phones when you go off-hook or
enable Do Not Disturb.
3. Tap to return to the idle screen.
The status you selected displays on the status bar (unless you selected Online).