This article on Arabic script typesetting and justification is turning out even better than I had hoped.

“My favourite resident of the block, and one of my favourite characters in all of Unicode, is U+FDFD, ﷽ : four-word invocation, bismillāh ar-raḥmān ar-raḥīm, as a single codepoint. A monument from the era when rendering was baked into the encoding because nobody trusted the renderer to do anything, preserved forever, like a fly in amber that recites.”

https://lr0.org/blog/p/arabic/

This character is amazing. Here's the glyph for it on my Android phone. I spent a fun fifteen or thirty minutes figuring out how it was composed. “Bismillah”, it transpires, is a contraction of “bismi Allah” (“in the name of God”), and in this one the "bismi" starts at farthest right and runs all the way through the tall part of the "ar-" in "ar-raḥman", with the ‘m’ part over on the left, and the mim's hanging final tail joining up with the ‘n’ of raḥman.

The "Allah" part is atop that, in the middle.

@mjd This was a bad form of the basmala, that we eventually fixed in Noto Naskh Arabic, but Android hasn’t updated its Noto fonts in ages (which is funny, given that Android is the reason Noto fonts exist at all).

Edit: the image below is the fixed version.

@khaled Thanks! Can you tell me: when you said "this" was a bad form, did you mean the "this" from https://mathstodon.xyz/@mjd/116748713103195512 or "this" from https://mathstodon.xyz/@[email protected]cial/116751032725791630 ?

If it's the first one I think I understand what you mean about the reading order and the fusion of the letters, but if it's the second one I do not.