Arabic Sukun Isolated Form

No; it is the same mark in a legacy form.

Sukun is the Arabic mark that says a consonant has no vowel after it. In ordinary Arabic writing, it follows its letter as a combining mark, as in بْ.

ﹾ is a spacing compatibility form corresponding to a space plus ْ. It can stand alone; the combining ْ is positioned over the letter before it. The spacing form does not add a different sound.

How did Arabic sukun marks develop?

Their writing developed through changing scribal systems.

Surviving Qur’an manuscripts in Hijazi, an early Arabic handwriting style, show consonant-distinguishing dots only sporadically in the first/seventh century—the seventh century CE, first in the Islamic calendar. These dots helped tell similar-shaped letters apart; they were part of a wider marking practice, not a complete guide to pronunciation.

The practical need was to guide reading when the written letters left some sounds open. Red-dot vocalization was standard in Qur’an manuscripts from the early eighth until the late tenth or eleventh century. A manuscript from the late eighth or ninth century shows a transition to letter-shaped vowel marks, but no separate sukun sign.

Which sukun should you type?

Use the combining sukun after the letter for ordinary Arabic.

Type the Arabic letter followed by U+0652 for regular text; this lets the text engine position ْ on the letter. Use ﹾ only when preserving legacy data or matching this exact spacing character.

The similar Qur’anic marks ۟ and ۠ can denote other things in some orthographies. Their resemblance does not make them substitutes for the ordinary sukun.