Titlo is an extended diacritic symbol used in old Cyrillic manuscripts, e.g., in Old Church Slavonic and Old East Slavic languages. The word comes from the word "title", borrowed from the Greek "τίτλος". The titlo was drawn as a zig-zag line over a text. One way was short stroke up, falling slanted line, short stroke up; another way was like a sideways square bracket: short stroke up, horizontal line, short stroke down. Titlo has several usages, the first two may be seen, for example, in the earlier manuscripts of the Slavic Primary Chronicle and in Russian icons.

One meaning was to modify letters in order to write down numbers, see Fig. 1, in a quasi-decimal system, similar to the Ionic numeral system of early Greece.

Another purpose was over-text abbreviation marks, used for words of importance, such as Tsar (Цесарь → Црь), Her Majesty (Государыня → Гня), God's Mother (Богородица → Бца), Jesus Christ (Иисус Христос → Ис Хс), God (Богъ → Бъ), Lord (i.e., god: Господь → Гь, see Fig. 2), etc.

However quite often the titlo was used to mark the place where a scribe accidentally skipped the letter, if there was no space to draw the missed letter above. A short titlo is used over a single letter or over the place of abbreviation; a long titlo was used over the whole word.

Still another usage was in church musical notation called kriuki ("hooks"), whose meaning is unfortunately lost.

Cyrillic titlo is provided in the Unicode as U+0483, not fully supported yet.