ChannelToken (non-numeric) and ChannelIdentifier (numeric) are used to store the unique identifier as defined by its source (Site).
This information is parsed out of the content during the Mapping phase of content item processing. So for example, on a Tweet, the ChannelIdentifier is the long numeric that Twitter assigned to uniquely identify the Tweet within their system. When
using this field, it is important to use the SiteId in combination with ChannelToken/ChannelIdentifier when looking up values based on this value since different sources may re-use the same value.
Proposed As Answer byRichard OrrFriday, February 03, 2012 11:57 PM