Studies on identified skeletal collections yield discordant results about the association between osseous changes and activity. These dissonances can be ascribed to several factors: the variability of the osseous changes selected for observation, the inconsistency of their interpretative criteria and the inhomogeneous classification of occupation, here used as synonym of profession, within each study. The need to standardize the concept of occupation in its biomechanical and socio-cultural expression is currently addressed by the authors, as members of a working group created after the workshop ‘Musculoskeletal Stress Markers (MSM): limitations and achievements in the reconstruction of past activity patterns’ (Coimbra University, 2009). Within this framework, the authors reviewed the literature dedicated to entheseal changes and functional adaptation of long bones, focusing their research on studies based on European identified skeletal collections and on the criteria used in each study to classify occupations. The aim of this research was to (i) assess agreements and disagreements between authors with regard to the criteria used to categorize occupation, and (ii) highlight the steps needed to build a classification system permitting future comparisons between collections of different chronological and geographical contexts. Data from the literature were exported to a table including the assessment criteria used to classify the occupation for each profession and the assignment of specific occupations to occupational categories. Overall, our results revealed two main issues: an ambiguous historical interpretation of occupation and a marked influence of the researcher's perspective on the criteria used to classify occupations. Therefore, although the table allows basic comparisons between collections, further research is needed in order to obtain shared classifications based on each profession's specifics. Copyright © 2013 John Wiley & Sons, Ltd.