Wikipedia
Letter Naviyani (ޱ) used to be the 19th letter of the Maldivian alphabet. This letter's former position in the alphabet was between letters Daviyani and Zaviyani.
Naviyani stands for the retroflex "n" sound common to most Indic languages ( Sinhala, Gujarati, Hindi, Tamil, etc.).
Letter Naviyani was abolished from official documents around 1953 by Muhammad Amin, the ruler of Maldives at that time. The reason why amongst all letters representing retroflex sounds, like Lhaviyani , Daviyani or Taviyani , this particular letter was abolished is not known. Perhaps it was a mere whim of that charismatic Maldivian leader.
The corresponding sound (phoneme ) is still pronounced in the Maldivian language. Nouns like "onu" (bamboo) or verbs like "bunung" (to say) have this phoneme. It sounds especially clearly in the speech of southern Maldivians.
This letter is still seen in writing in reprints of traditional old books, written before the 1950s, like the Bodu Tartheebu, an ancient religious book. It is also used by Addu people when writing songs or poetry in their language variant.
In 2000, when the Tāna script was put into Unicode, certain Maldivian government officials didn't see the need to include this letter. Now, however, there is a minor movement for the reinstating of this letter, especially among Addu intellectuals, whose goal is to bring letter Naviyani back into currency.