Mahmud al-Kashgari in the context of "Dīwān Lughāt al-Turk"

The Kayı (Karakhanid: قَيِغْ, romanized: qayïġ; Turkish: Kayı boyu, Turkmen: Gaýy taýpasy) were an Oghuz Turkic ethnic group and a sub-branch of the Bozok tribal federation. In his Dīwān Lughāt al-Turk, the 11th century Kara-Khanid scholar Mahmud al-Kashgari cited Kayı as of one of 22 Oghuz tribes, saying that Oghuz were also called Turkomans.

The name Kayı means "the one who has might and power by relationship" and a Turkmen proverb says that "the people shall be governed by Kayı and Bayat tribes" (Turkmen: Il başy - gaýy-baýat).

The Oghuz languages are a sub-branch of the Turkic language family, spoken by approximately 108 million people. The three languages with the largest number of speakers are Turkish, Azerbaijani, Turkmen which, combined, account for more than 95% of speakers of this sub-branch.

Kara-Khanid scholar Mahmud al-Kashgari, who lived in the 11th century, stated that the Oghuz language was the simplest among all Turkic languages.

Tüger, Döğer, Dogar or Deogers (Azerbaijani: Dögərlər, Turkish: Döğer boyu, Turkmen: Tüwer taýpasy) was one of the 24 Oghuz tribes from the Bozok wing, the tribe of Ay Khan. According to Mahmud Kashgari, it was the eighteenth biggest tribe among the Oghuz tribes. The Turkoman dynasty of Artuqids, which ruled the Beylik of same name, originated from the tribe of Döger.

Karakhanid, also known as Khaqani Turkic (lit. meaning 'imperial' or 'royal', self referring to as 'Türki' or 'Türkçe'), was a Turkic language developed in the 11th century during the Middle Turkic period under the Kara-Khanid Khanate. It has been described as the first literary Islamic Turkic language. It is sometimes classified under the Old Turkic category, rather than Middle Turkic, as it is contemporary to the East Old Turkic languages of Orkhon Turkic and Old Uyghur. Eastern Middle Turkic languages, namely Khorezmian Turkic and later Chagatai are descendants of the Karakhanid language.

Karakhanid vocabulary was influenced by Arabic and Persian loanwords, but the language itself was still noted to be similar to the Old Uyghur language. The language was written using the Arabic script. Mahmud al-Kashgari's Dīwān Lughāt al-Turk and Yūsuf Balasaguni's Kutadgu Bilig are considered to be important literary works written in Karakhanid language.

The word Japan is an exonym, and is used (in one form or another) by many languages. The Japanese names for Japan are Nihon ([ɲi.hoꜜɴ] ) and Nippon ([ɲip.poꜜɴ] ). They are both written in Japanese using the kanji 日本.

Since the third century, Chinese called the people of the Japanese archipelago something like "ˀWâ" (倭), which can also mean "dwarf" or "submissive". Japanese scribes found fault with its offensive connotation, and officially changed the characters they used to spell the native name for Japan, Yamato, replacing the 倭 ("dwarf") character for Wa with the homophone 和 ("peaceful, harmonious"). Wa 和 was often combined with 大 ("great") to form the name 大和, which is read as Yamato (see also Jukujikun for a discussion of this type of spelling where the kanji and pronunciations are not directly related). The earliest record of 日本 appears in the Chinese Old Book of Tang, which notes the change in 703 when Japanese envoys requested that its name be changed. It is believed that the name change within Japan itself took place sometime between 665 and 703. During the Heian period, 大和 was gradually replaced by 日本, which was first pronounced with the sound reading (on'yomi) Nippon and later as Nifon, and then in modern usage Nihon, reflecting shifts in phonology in Early Modern Japanese. In 1076, Turkic scholar Mahmud al-Kashgari in his book Dīwān Lughāt al-Turk mentioned this country as 'Jabarqa' (جَابَرْقَا). Marco Polo called Japan 'Cipangu' around 1300, based on the Chinese enunciation of the name, probably 日本國; 'sun source country' (compare modern Min Nan pronunciation ji̍t pún kok). In the 16th century in Malacca, Portuguese traders first heard from Indonesian and Malay the names Jepang, Jipang, and Jepun. In 1577 it was first recorded in English, spelled Giapan. At the end of the 16th century, Portuguese missionaries came to coastal islands of Japan and created brief grammars and dictionaries of Middle Japanese for the purpose of trade. The 1603–1604 dictionary Vocabvlario da Lingoa de Iapam has 2 entries: nifon and iippon. Since then many derived names of Japan appeared on early-modern European maps.

A tamga, or tamgha (from Old Turkic: 𐱃𐰢𐰍𐰀, romanized: tamğa, lit. 'stamp, seal'), was an abstract seal or brand used by Eurasian nomads initially as a livestock branding, and by cultures influenced by them. The tamga was used as a livestock branding for a particular tribe, clan or family. They were common among the Eurasian nomads throughout Classical Antiquity and the Middle Ages. As clan and family identifiers, the collection and systematic comparison of tamgas is regarded to provide insights into relations between families, individuals and ethnic groups in the steppe territory.

Similar tamga-like symbols were sometimes adopted by sedentary peoples adjacent to the Pontic–Caspian steppe both in Eastern Europe and Central Asia. Branding of livestock was a common practice across most sedentary populations, as far back as the ancient Egyptians.

Sart was a term used in the history and ethnography of Iran and Central Asia. The term was commonly applied to sedentary Turks and Tajiks in Central Asia. Usually bilingual in Turkic and Persian, they belonged to the same cultural tradition and occupied the same economic role.

The Kazakhs, Kyrgyz and Turkmen, being proudly devoted to their rural, nomadic ways of life and values, strongly disliked the highly Persianized speech of Turkic by the Sarts. This instance is comparable to the prejudice the 11th century Turkic scholar Mahmud al-Kashgari had displayed toward Sogdianized urban Turks. Meanwhile, the Persian Tajik dialect had been adopting Turkic vocabulary and syntax, which caused it to shift away from standard Persian.