Tittle

From Medieval Latin titulus ("small stroke, diacritical mark, accent"), from Latin titulus ("title").

Full definition of tittle

(plural tittles)

A small, insignificant amount (of something); a vanishing scintilla; a measly crumb; a minute speck.
Any small dot, stroke, or diacritical mark, especially if part of a letter, or if a letter-like abbreviation; in particular, the dots over the Latin letters i and j.

1590, Bales, The Arte of Brachygraphie (quoted in Daid King's 2001 'The Ciphers of the Monks'):The foure pricks or tittles are these. The first is a full prick or period. The second is a comma or crooked tittle.
1965, P. A. Marijnen, The Encyclopedia of the Bible:The words "jot" and "tittle" in this passage refer to diacritic marks, that is, dashes, dots, or commas added to a letter to accentuate the pronunciation.
1987, Andrea van Arkel-De Leeuw van Weenen

, MÃ¶Ã°ruvallabÃ³k, AM 132 Fol: Index and concordance, page xii:

(the page calls both "a superscript sign (hooklike)" and also a diacritical abbreviation of "" () "tittles")
2008, Roy Blount, Alphabet juice: the energies, gists, and spirits of letters:A tittle is more or less the same thing (the dot over an i, for instance), except that it can be traced back to Medieval Latin for a little mark over or under a letter, such as an accent ague or a cedilla. I don't know whether an umlaut is one or two tittles. Maybe it's a jot and a tittle side by side.