T'Lani III was the third planet in its star system. This planet was formerly inhabited by the T'Lani species, until the entire population was wiped out by Harvesters, deployed during the war against the Kellerun that ended in 2370.
Miles O'Brien and Julian Bashir hid in an abandoned command center on T'Lani III after the T'Lani and Kellerun authorities attempted to eliminate them and their knowledge of the Harvesters. (DS9: "Armageddon Game")
See also
According to the script, the pronunciation for T'Lani was "tuh-LA-nee". [1]
According to StarTrek.com, this planet orbited a star named T'Lani, and according to Star Trek Encyclopedia, 4th ed., vol. 2, p. 356, in the entry for "T'Lani Prime", the system was named also T'Lani. [2](X)
The surface of T'Lani III was depicted via a modified version of the matte painting previously used for the surface of Turkana IV, with new structures added in the foreground.