Reading a Cluster, and What the Headline Does

The horizontal line running along the top of a Devanagari word, the shirorekha, is what makes the script's vertical stacking legible. Vowel signs are hung above it, below the letters, and to either side; conjuncts fuse two or three consonants into one sign; and this letter attaches as a mark above the line or a stroke below it. Without a continuous headline to anchor them, those marks would float free of the letters they belong to. The headline also determines where a word breaks, since it runs unbroken across a word and stops at its end, so a reader identifies word boundaries by the gaps in the line rather than by spaces alone. In older manuscripts the line is drawn as the scribe writes each letter and the word divisions are often not marked at all, which is one of the things that makes an unedited manuscript harder to read than a printed edition.

The headline is inherited from the Brahmi-derived hands out of which Devanagari developed, where it began as a serif at the top of each letter and gradually joined up across the word, a development traceable through the inscriptional record that Richard Salomon's guide to Indian epigraphy surveys. This atlas records the letter's place, its articulation and its combining behaviour, and assigns it no numerical value, because the Sanskrit tradition assigns none to individual letters.