Taschdid
Shadda or tashdīd is an optional script from the Arabic script indicating a doubling of consonant.
In the Arabic script, instead of two identical consecutive consonants, only one single consonant is written. Since the doubling can cause a change of meaning, the shadda is also regularly found in other unconfirmed texts.
In the event that the shadda follows after a vignette fatha, little alif, kasra, damma or sukun, then the vignette signs are written above, or in the case of the kasra also below, the shadda and not directly above or below the consonant In other words, the shadda is in between the consonant and the sound sign in such cases.
Remarkably, the Arabic word for God, الله Allah, is written with a double letter ل and a shadda above one of them. Shadda in Unicode
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