PLANET VIP-2020PT - Manual (Page 35)

Enterprise HD PoE IP Phone
VIP-2020PT
Presence
Presence is called present, and compared to the BLF, it can also check whether object is online.
User can subscribe to the BLF and presence station of the same number at the
same time.
MWI (Message-Waiting Indicator)
When the key is configured as MWI, User is allowed to access voicemail quickly by pressing this
key.