Sindhi language features
Fonts which are intended to support the Sindhi language must include some different design features than those designed for standard Arabic. In every case, the blue is what a Sindhi font should support.
The lam-alef ligature should be designed in a Sindhi-style.
Sindhi lam-alef.
The meem should have a short tail.
Sindhi meem.
There is some disagreement on which heh codepoint should be used for Sindhi. The shape of the character is not in disagreement, but which codepoint should be used is not clear. SIL has chosen to use ه , and the Sindhi Language Authority has used ھ .
Sindhi heh.
When a kasra is used in context with the shadda, most Arabic fonts will move the kasra up and ligate it below the shadda. This should not happen for Sindhi support. The kasra should remain below the base. Also, note that diacritics on isolate and final forms of characters are left offset to the nukat.
Sindhi shadda-kasra.
The Sindhi style of comma and semi-colon ( ، and ؛ ) is to be downward rather than upward. Instead of making this a glyph variant, the Unicode Standard says to use different codepoints, namely ⹁ and ⁏ .
Sindhi comma and semi-colon.
Sindhi has a different style of digits for ۶ and ۷ .
Sindhi digits.