message; informative matter
contacting; getting in touch; communication; call; message
(connecting) passageway; accessway; walk-through; skyway; sky bridge
contact network; phone tree; contact information for relevant people (in a given organization)
liaison group; liaison committee; liaison council
correspondence notebook (e.g. between teacher and parents); contact notebook; communication notebook
de-facto embassy; liaison office
connecting station; station where you change
undeliverable item notice
de-facto embassy; liaison office
connection (interline) ticket
joint carriage; through-ticketing; transportation of passengers or freight handled by two or more companies via an arrangement