This is a list of unusual destinations you may see in call history and what they equate to:

nms - Caller hung up during the auto attendant
ToggleAvailability - This shows a user has logged into or out of a queue
SpeakAccount - The Caller hung up during the voicemail message but before leaving a voicemail
VMail (xxx) - The caller left a voicemail at the extension listed in the brackets
vmail - This shows a user calling the voicemail system to check their voicemail
Auto-Attendant - Caller hung up during the auto attendant reading out voicemail options