Sentence:  A <WSD>tittle</WSD> 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 <WSD>tittles</WSD>. Maybe it's a jot and a <WSD>tittle</WSD> side by side. 
Meaning of the word marked with <WSD> tags:  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).