ASCII Compatible Romanization

[Nachtswalbe]

Romanizations can and do include apostrophes, accent marks and the like. However, accent marks are difficult to type on English-language keyboards, and it is easier for English-based HTML, URLs to display ASCII characters.
For languages like Hindi and Arabic, ASCIIfications exist. However these rely on distinctions between capitall and lowercase letters, which is inefficient and unaesthetic.
This can also be extended to languages traditionally written in the Latin alphabet with diacritics, like French.

Arabic:
/b t d tˤ k q/ <b t d tc k q>
/d dˤ d͡ʒ f/ <d dc j f>
/s sˤ ʃ x ~ χ ħ h/ <s sc sh kh hc h>
/ð z ðˤ ~ zˤ ɣ ~ ʁ[k] ʕ/ <dh z zc gh c>
/ʔ m n w r l j/ <x m n w r l y>
/a i u a: i: u: aj aw/ <a i u aa ii uu ay aw>

examples:
ṭabīb, "doctor" --> Tcabiib
/ʔa.tˤib.baːʔ/ "doctors, m.pl" --> xatcibbaax
أحجية <xuhcjiyya>

[Raphael]

No problem - just write a first draft in Unicode, then convert it to hexadecimal.

(I'm joking, in case that wasn't clear.)

[fusijui]

For the first decade or so of my online conlanging life (30 years ago now!) ASCII was the only option for conlangs and for phonetic/phonemic transcriptions; even now I remember the struggles between X-SAMPA and Kirschenbaum versions of IPA

Polite struggles, in retrospect; the internet was different back then, and the nerdbro was not yet an icon.