Autocomplete or word completion software has been developed to facilitate and accelerate keyboard input and it works with most word processing software, but also in software that involves text fields (messaging, forms, search bars and text fields, internet browsing, etc.). In this article, we will deal about the challenges of digital materiality by observing the functioning of autocompletion software which calls into question the relationship between constraint and possibility within digital writing practices. We are going to observe in particular the plasticity of the linguistic signifier, analyzed from the point of view of digital materiality, while taking into account two complementary approaches - the semiotics and the linguistics of texts and speeches - and two levels of observation - from words to text and from text to genre - developed around a single object of analysis, mobilizing notions of standard, usage, token, but also those of sign, text, genre.