This chapter takes a look at the orthography of Lingua Franca in the Dictionnaire de la langue franque and examines the sound inventory and phonological processes that the orthography reflects. Following preliminary observations (Section 4.1), the chapter discusses the orthographic representation and phonological processes of Lingua Franca vowels (in Section 4.2) and consonants (in Section 4.3). Section 4.4 addresses the aspects of Lingua Franca phonology revealed by the phonological adaptation of French words. Section 4.5 zooms in on the various influences on the Dictionnaire’s orthography, expanding and supplementing the earlier discussion of this issue in Chapter 3. Section 4.6 summarizes the main issues, situating the sound inventory of Lingua Franca in the context of the hypothesized role of inter-Romance koineization in its genesis.