When the set of tabs used fluctuate, the memory of which number
belongs to which chat becomes difficult to work with. Non-numbers
can be used to navigate tabs with `/win`, however, it is difficult
to know which letters are required to select a certain tab.
This option introduces a display mode for tab names where only the
unique prefix of the tab name is shown, saving space and providing
with a minimal string which can be used with `/win`.
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