Here is a list of all documented namespace variables with links to the namespaces they belong to:

BTEndpointType : Ice
BTSEndpointType : Ice
iAPEndpointType : Ice
iAPSEndpointType : Ice
SSLEndpointType : Ice
TCPEndpointType : Ice
UDPEndpointType : Ice
URIEndpointType : Ice
WSEndpointType : Ice
WSSEndpointType : Ice