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To set -use-tray-icon as a command line parameter for Signal so that it uses a tray icon by default, follow the following steps: You can also have Signal start in the system tray by passing -start-in-tray as a command line parameter, in which case the window will start minimized to the system tray ( see relevant source code). Unfortunately, Signal won't display any desktop notifications when minimized to the tray and it won't be able to flash its window frame like it normally does when it receives a message, so you might want to also turn on the Play audio notification setting in File > Preferences so that you don't miss messages.When you receive a message, the Signal tray icon will display a small red visual indicator.
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