Open AccessSignatures will be read as (un)stable traces of professional knowledges, practices, and identities. The paper intends to propose a theoretical framework to explore the sociomateriality of signature in occupational and professional practices. This exploration will be conducted by assuming a practice-based approach to “signing in practice” and therefore by paying attention to knowing as a situated practice within organizations. The aim of the paper is to invite to a line of research that considers signatures—in occupational and professional practices—as “matters of fact,” i.e. stable traces resistant to disputation that “make” the professional accountable, and as “social fabrications,” i.e. traces which emerge from professional learning and knowing, thus resulting from stable negotiations of human and nonhuman assemblages.