A text message (or TEXT MSG) was a typed communication sent from one computer panel to another. Starfleet ships enabled this ability, which was sometimes used when verbal contact could be dangerous, or was impossible.
In 2153, after his apparent execution at the hands of Triannon religious extremists under D'Jamat (less technologically advanced than Humanity, they did not bat an eye when he claimed that the transporter was in fact a disintegration chamber) who had taken over the ship, Captain Jonathan Archer, needing to keep up the illusion that he was dead, contacted Dr. Phlox in sickbay from an access corridor at the bottom of the ship to ask how to disable the explosives the extremists had in their body. (ENT: "Chosen Realm")
In 2379, after Shinzon had destroyed the viewscreen of the USS Enterprise-E, Captain Jean-Luc Picard hailed him and sent a text message to Deanna Troi, who was at the helm, to ram the Scimitar on his command. (Star Trek Nemesis)