This chapter is intended to offer assistance for the linguistic description of writing systems throughout the history of one or, especially, several languages and provide a comparative description of the different units of writing systems. The first section establishes the definitions of the concepts of grapheme, graph, allograph and suprasegmental grapheme. The application of these concepts to English and Romance languages is exemplified by three models and methods of diachronic and comparative description of writing systems: Romance scriptology, cultural history of European orthographies, and comparative graphematics of punctuation. The second section discusses biscriptality, the phenomenon of employing two or more writing systems for the same language, not rare in the history of languages from different families, and related to different aspects of society and language users. With examples mainly from Russian and other Slavic languages, biscriptality is shown to be present on several levels of written language, and various applications of biscriptality are characterized with the help of dichotomies such as synchronic vs. diachronic biscriptality, monocentric vs. pluricentric biscriptality, and societal vs. individual biscriptality.

This chapter provides a brief introduction to grapholinguistics, focusing mainly on its core subdisciplines – graphetics and graphematics (or graphemics). Historically, grapholinguistics can be perceived as a neglected subdiscipline of linguistics, though it also explores the topic of written language in its totality, which is not entirely linguistically oriented. The author specifies that its beginnings, as an organized movement, date back to Germany of the 1970s, but various instances of grapholinguistics emerged at different places (and in different languages). The field now has an established textbook, a special section in the online Dictionaries of Linguistics and Communication Science, and, as of quite recently, a proposal for a unifying general theory. This chapter is centered on graphetics and graphematics in order to expose the crucial linguistic dichotomy – that between form and function. Whereas the primary concern of graphetics is the materiality of writing, graphematics deals mainly with the functions of abstract units. The interplay between these two interrelated grapholinguistic subdisciplines is especially evident in the analysis of allography, which focuses on the variation of both concrete and abstract units (graphs and graphemes, respectively).