6. Phags Pa Script / Square Script
Pagva Bichig / Dörvöljin Bichig
Invented in 1269 by Phags Pa Lama for Khubilai Khan, this script was adopted for official documents in the Yuan dynasty. The letters of this syllabic alphabet are based on his native Tibetan script but contain other influences such as being written vertically like the Uighur Script and grouped into syllables like Khitan Small Script. This script was intended to be a universal script for all languages spoken in the Mongol Empire including Mongol, Arabic, Tibetan, Chinese, Sanskrit and Turkic. It did not replace the traditional writing systems of the respective peoples and ceased being used in 1368 with the fall of the Yuan dynasty. Also transcribed "hPags-Pa".
7. Clear Script
This alphabet, developed in 1648 by Zaya Pandit Namhaijamts (1599-1662), was intended mainly for Oirat but also for Mongol, Samgard, Tibetan and Sanskrit. This is based on the Classical Mongol Script with ambiguous letters, such as 'O' and 'U', differentiated to be more clear cut. This was used by Oirats in the region between the Ijil River, Ezen River and Kökö Lake. It is still used today by Oirats in Shinjaan.
8. Soyombo Script
This syllabary was developed by (Buddhist) Saint Zanabazar in 1686. The name means "Self developed Holy Letters" in Samgard. It was intended to accommodate Mongol, Samgard, Tibetan and for transcribing foreign words. It is typically written from left to right but can be written from top to bottom. Soyombo never widely caught on because it was too difficult to use. Though it has seen some regular use in official capacities such as official seals. It also became a focus of national pride under Bogd Khaan. It's most lasting legacy is the initial symbol of the script being incorporated into the flag of Mongolia.
9. Horizontal Square Script
Hevtee Dörvöljin Üseg
Another syllabary developed by (Buddhist) Saint Zanabazar around the same time as Soyombo. It contains some influence of the Korean Script (Hunmin chong'um). It is written from left to right and can be used for Mongol, Samgard and Tibetan. Since its rediscovery in 1801, it's actual usage remains unknown.
10. Vaghintara Script
This alphabetic script was developed in 1905 by a Buryat monk named Agwan-Dorji (1850-1938) as a variation of Uighur Script with less ambiguity. A notable change in this alphabet is that the letters no longer have three different forms. Rather a single form, based on the Medial of the Old Mongol Script, is used regardless of position in the word. The name of this script is based on the Sanskrit translation of the inventor's first name. It was intended to accommodate transcribing Russian words as well. Its use is limited to about ten books printed until 1910 when financial problems prevented him from continuing to promote the alphabet.
11. Latin Alphabet
The earliest known use of Latin letters to write Mongol is with the transcription of Mongol words into the journals of the European travelers in the 13th century such as John Plano of Carpini, William of Rubrick, and later Marco Polo. An attempt was made to develop a system of using Latin letters for Buryat between 1921 and 1931, when it was implemented. But it was short lived as it was replaced by Cyrillic in 1937 under Russian influence. Mongolia also officially adopted the Latin alphabet on February 1st, 1941 but then annulled the law two months later, on March 25th, as it did not cover all the sounds in Mongol and proved too difficult to utilize.
12. Cyrillic Alphabet
The Cyrillic alphabet used for Mongolian is directly based on the Russian alphabet with the addition of two vowels derived from Old Cyrillic. It is said that Stalin got upset with the plethora of alphabets used by the various Russian territories acquired in their Tsarist colonial days, including Buryatia, Georgia and Armenia, as well as the satellite nations added in the early days of the Soviet Union. So he mandated that people under his control use Cyrillic for their respective languages. Cyrillic, with special additions tailored to Buryat Mongol, was adopted in Buryatia in 1937, and officially in Mongolia on May 9th, 1941, but was not implemented there until the beginning of 1946.