What 𑁦 means
It belongs to positional digits, not older additive signs.
Older Brahmi numbers used separate signs for units, tens, hundreds and thousands. Later digits use place value: 𑁧𑁦 means ten; both sets coexisted.
The Bakhshali, an Indian math manuscript, has placeholder dots. Oxford's 2017 report dated some Bakhshali leaves to the 3rd or 4th century, not the text as a whole. Those dots led to hollow zeroes; Brahmagupta treated zero as a number by 628. The Gwalior inscription, commonly dated 876, shows a hollow zero. Arabic scholarship carried Indian place-value arithmetic west.
Don't confuse it with
4Questions people ask
1Why does 𑁦 show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type 𑁦
𑁦\11066Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.