Old Uyghur Combining Dot Below

It marks a base letter, not a word. An Old Uyghur dot is a diacritic: one of four dot signs used to distinguish letters that had merged or mark a sound with no separate letter. Its reading depends on the base and spelling context, so alone it has no fixed reading.

Why did Old Uyghur use dot marks?

Dot signs helped keep merged letters distinct. Old Uyghur developed from the cursive style of Sogdian, a Central Asian script, in the eighth or ninth century; it later became an ancestor of Mongolian writing. It first wrote medieval Turkic languages, then also Chinese, Mongolian, Tibetan, and Arabic. The wider script is attested in ninth-century documents.

By the 11th century, two letter names, samekh and shin, had merged into the shape of Old Uyghur letter 𐽿. A separate mark, two dots below, distinguished the shin reading from samekh; that spelling uses 𐾅, not this one-dot mark.

How do I type the Old Uyghur dot below?

Write the base letter first and the dot after it. The mark has no separate input position; attach it to the Old Uyghur letter it modifies.

A font without Old Uyghur support can leave it detached or invisible. Square and cursive styles vary across regions and over time; Old Uyghur's default layout is horizontal, read right to left, while traditional vertical columns run left to right.