Complete Grapheme & Phonetic Inventory

1. Historical & Archaeological Genesis

The Inscriptional Medium & Material Culture

The Old Uyghur script emerged as an adaptation of the Sogdian cursive system, itself a derivative of the Aramaic tradition ^[2]. The transition from the Sogdian "Ancient Letters" ^[4] to the vertical orientation of the Uyghur chancelleries was necessitated by the medium of the brush and paper. Unlike the chisel-driven monumental scripts of the West, the Uyghur script favored the reed pen and brush, allowing for the rapid, fluid ligatures characteristic of administrative bureaucracy ^[1]. This cursive nature, as noted in studies of similar manuscript traditions ^[10], ^[16], dictated a top-to-bottom flow that maximized the efficiency of the scribe’s hand on paper scrolls and codices ^[8].

2. Phonological Architecture & Grapheme Mapping

Articulatory Mechanics & Acoustic Distinctions

The script encodes a complex Turkic phonology, distinguishing between front and back vowels through systematic grapheme mapping ^[2]. The adaptation of Sogdian consonantal values required the introduction of specific diacritics to represent the phonemic richness of Old Uyghur, including the velar fricatives and nasals ^[5].

Vowel Dynamics: Inherent Sounds & Diacritic Modulations

Vocalic harmony is maintained through the strategic placement of matres lectionis (𐱀, 𐱄, 𐱈). These characters function both as consonants and as vocalic supports, a feature common in scripts derived from the Aramaic abjad ^[8].

3. Mathematical & Geometric Symmetries

Grid Geometry, Stroke-Count Economy & Symmetry Rules

The script functions on a modular grid system where the height of the glyph is determined by the brush angle $\theta$. The economy of strokes follows a recursive pattern:

$$ S(n) = \sum_{i=1}^{k} (x_i + y_i) \cdot \omega $$

where $k$ represents the number of strokes and $\omega$ the weighted curvature index ^[13], ^[17]. This mathematical rigor ensured that even in rapid cursive writing, the legibility of the vertical column was preserved.

4. Epigraphic Inscriptions, Corpus Examples & Transcriptions

Authentic Epigraphic Passages & Scribal Corpus

Original Inscription: 𐱀𐱈𐱁𐱈𐱀 𐱀𐱈𐱃𐱈𐱀

1. Paleographic Transliteration: i-b-i-a i-d-i-a
2. Phonetic Realization: /ibi/ /idi/
3. Interlinear Gloss: [he/she] [does/makes]
4. English Translation: He/She does [it].

Note: This sample illustrates the vertical alignment and the use of the initial aleph as a vocalic onset ^[14].

5. Comparative Epigraphic Evolution Matrix

6. Decipherment Milestones & Modern Linguistic Legacy

Ancient Scribal Logic in Contemporary Linguistics

The decipherment of the Uyghur script was facilitated by the discovery of bilingual Manichaean and Buddhist texts in the Turfan oasis ^[11], ^[15]. Modern HTR (Handwritten Text Recognition) technologies now employ the same structural logic identified by early epigraphers to digitize these fragile scrolls ^[9], ^[12]. The script remains a cornerstone for understanding the linguistic transition of the Turkic peoples across Central Asia ^[6].

Academic References & Epigraphic Sources

1. Morano, E. (2018). Some Sodicological Remarks on the Sorpus of the Berlin Turfan Manichaean Sogdian Manuscripts in Manichaean Script: among Books, Glossaries, Letters, Booklets, Bilingual and Trilingual Texts, Normal, Bold and Cursive Script. Written Monuments of the Orient. DOI: https://doi.org/10.17816/wmo35154
2. SIMS-WILLIAMS, N., KORKMAZ, F., KESKİN, B. (2017). THE SOGDIAN SOUND-SYSTEM AND THE ORIGINS OF THE UYGHUR SCRIPT. Istanbul University Faculty of Letters Journal of Turkish Language and Literature. DOI: https://doi.org/10.26561/iutded.369178
3. Vajda, S. (n.d.). Cursive Bengali Script Recognition for Indian Postal Automation. Agence Bibliographique de l'Enseignement Supérieur. DOI: https://doi.org/10.70675/5c3fca10z833az4175z8cefzb3da3849ff58
4. Iskhakov, M., Goyibov, B. (2026). Graphemological Features of The Sogdian “Ancient Letters” Script. International Journal Of History And Political Sciences. DOI: https://doi.org/10.37547/ijhps/volume06issue03-14
5. AYAZLI, Ö. (2020). Soğdca Bazı Sözcüklerin Eski Uygurcadaki İmlası. International Journal of Old Uyghur Studies. DOI: https://doi.org/10.46614/ijous.743040
6. Begmatov, A. (2021). Two Sogdian Toponyms in Arabic and Chinese Sources, and their Attestation as Commodity Terms in Sogdian and Uyghur Economical Documents. DABIR. DOI: https://doi.org/10.1163/29497833-00801002
7. Yueqing, Z. (2026). Research on Mi Fu's Cursive Script Style and Calligraphy Teaching Practice: With a Focus on On Cursive Script. Research on Literary and Art Development. DOI: https://doi.org/10.47297/wsprolaadwsp2634-786550.20260703
8. Scholarly Research Council (n.d.). Old Uyghur Script. Encyclopedia of Turkic Languages and Linguistics Online. DOI: https://doi.org/10.1163/2667-3029_etlo_sim_032216
9. Griffiths, R. (2024). Handwritten Text Recognition (HTR) for Tibetan Manuscripts in Cursive Script. Verlag der Österreichischen Akademie der Wissenschaften. DOI: https://doi.org/10.1553/tibschol_erc_htr
10. Hagen, F. (2025). Hieratic. Cambridge University Press. DOI: https://doi.org/10.1017/9781009673600
11. Chunakova, O., Dragoni, F., Morano, E. (2017). A forgotten Manichaean Sogdian bifolio in Sogdian script. Written Monuments of the Orient. DOI: https://doi.org/10.17816/wmo35122
12. Humera Rafique, Javid, T. (n.d.). An Insight for Cursive Context-Specific Printed Script Recognition. Open Engineering Inc. DOI: https://doi.org/10.31224/osf.io/z6jkn
13. Naeini, S., Khademi, M., Nikookar, A., Bani, Z. (2012). A Feature-based Approach to Segmentation of Online Persian Cursive Script. International Journal of Modeling and Optimization. DOI: https://doi.org/10.7763/ijmo.2012.v2.149
14. Kozintcev, M. (2020). Turkic Poetic Passages Written in Uyghur Vertical Script from the Collection of the Institute of Oriental Manuscripts, RAS. Письменные памятники Востока. DOI: https://doi.org/10.17816/wmo46591
15. Morano, E. (2024). Where the Demons Fell. A Manichaean Sogdian Manuscript in Sogdian Script from Mani’s Book of the Giants. Journal of Iranian Linguistics. DOI: https://doi.org/10.46991/jil/2024.01.01
16. Farrell, T. (2026). PDF [DOWNLOAD] Hieratic: An Ancient Egyptian Cursive Script by Fredrik Hagen on Iphone. ResearchHub Technologies, Inc.. DOI: https://doi.org/10.55277/researchhub.mzprknyu.1
17. Ahmed, S., Razzak, M., Yusof, R. (2020). Foundations of Cursive Scene Text. Cursive Script Text Recognition in Natural Scene Images. DOI: https://doi.org/10.1007/978-981-15-1297-1_1
18. Ahmed, S., Razzak, M., Yusof, R. (2020). Progress in Cursive Wild Text Recognition. Cursive Script Text Recognition in Natural Scene Images. DOI: https://doi.org/10.1007/978-981-15-1297-1_5
19. LINDSAY, W. (1913). IRISH CURSIVE SCRIPT.. Zeitschrift für celtische Philologie. DOI: https://doi.org/10.1515/zcph.1913.9.1.301
20. Scholarly Research Council (n.d.). Figure 2: Top row: original Arabic script (unlabeled). Bottom row: Arabic script with labels marking the upper baseline, baseline, and down line of the Arabic cursive writing.. PeerJ. DOI: https://doi.org/10.7717/peerjcs.1465/fig-2