ʔalif ḵanjariyya is a rare diacritic, is missing on standard keyboards and is sometimes replaced with a fatḥaـَ(-a) in a vocalised Arabic text or omitted altogether, except in the Qur'an.
ʔalif ḵanjariyya can be written with or without a fatḥa, e.g. with a fatḥa رَحْمَٰن(raḥmān) in the Middle East or without a fatḥa رَحْمٰن(raḥmān) in South Asia (Pakistan, India and Bangladesh)
The word اللّٰه(allāh, “Allah”) is usually produced automatically by entering "alif + lām + lām + hāʾ" - الله (read from right to left). The word consists of ا(ʔalif) + ligature of doubled ل(lām) with a shaddaـّ and an ʔalif ḵanjariyya above ل(lām).
In Wiktionary we use ʔalif ḵanjariyya to generate a correct transliteration ("ā") and to indicate a long /aː/. A fatḥa alone, without ʔalif ḵanjariyya or a long alif ا(ʔalif) would be transliterated as a short /a/.
