For over a thousand years, Azerbaijani poetry has been written not only in its native language, but also in Arabic and Persian, and has developed in constant contact with the wider Oriental literary context, so it has adopted thousands of Arabic and Persian words into its vocabulary over the past centuries. Having used Arabic script for twelve centuries, Azerbaijan underwent three alphabet changes in the 20th century. After the transition to Cyrillic and Latin, an apostrophe was added to the alphabet after 32 letters in order to ensure undistorted pronunciation of words of Arabic origin containing the letter ayn and the mark of hamza in the Azerbaijani script. This contributed to the undistorted pronunciation of Arabic words used in the Azerbaijani language, the correct comprehension of their meanings and the correct sounding of national poetry in the aruz meter. However, due to the lack of proper understanding of the historical significance of the apostrophe in the Azerbaijani language, and by disregarding the obstacles that its absence would create for the understanding of classical Azerbaijani poetry by modern generations, this punction mark was abolished. Consequently, in recent years serious misunderstandings have arisen regarding the meaning of works of classical Azerbaijani literature published without apostrophes. As a result of the analysis of the literary heritage of many Azerbaijani classical poets, it was established that there are more than 900 words that require an apostrophe. In the modern Azerbaijani language, there are about 200 words that are necessarily to be written with an apostrophe. The article emphasizes the need for the restoration of apostrophe in a view of its regulating function between Azerbaijani orthography and orthoepy, its significance in the publication, study and use of classical poetry, its role as a bearer of tradition and a connecting bridge between the classical and modern literary language of Azerbaijan.