Sagot :
It's called tittle or superscript. This name applies for both "i" and "j"
That "dot" is called a tittle or a superscript dot . A tittle or a superscript dot is a small distinguishing mark, it shows in the lower case letter(s) i or j. The tittle is an integral part of the glyph of i and j, but diacritic dots can appear over other letter in various languages.