The modifier letter right half ring ( ʾ ) is a character found in Unicode in the Spacing Modifier Letters range (although it is not a modifier, but a standalone grapheme).^[1] It is used in romanization to transliterate the Semitic abjad letter aleph and the Arabic letter hamza after it was used by The Encyclopedia of Islam (later the International Journal of Middle East Studies),^[2] representing the sound [ʔ] (a glottal stop, as in Arabic ء hamza). In informal contexts, the backtick ⟨ ` ⟩ or the apostrophe ⟨ ' ⟩ is commonly used as a substitute; but this can lead to confusion with the modifier letter left half ring.

• Half ring
• Glottal stop (letter)
• Spiritus lenis – Diacritical mark (᾿) used in polytonic orthographyPages displaying short descriptions of redirect targets
• Sicilicus – Diacritical mark in old Latin