Introduction. The study describes the conditions for long-term preservation of the content of the institutional repositories of Swedish higher education institutions based on an investigation of how deposited files are managed with regards to file format and how representatives of the repositories describe the functions of the repositories.
Method. The findings are based on answers to a questionnaire completed by thirty-four institutional repository representatives (97% response rate).
Analysis. Questionnaire answers were analysed through descriptive statistics and qualitative coding. The concept of information infrastructures was used to analytically discuss repository work.
Results. Visibility and access to content were considered to be the most important functions of the repositories, but long-term preservation was also considered important for publications and student theses. Whereas a majority of repositories had some form of guidelines for which file formats were accepted, very few considered whether or not file formats constitute open standards. This can have consequences for the long-term sustainability and access of the content deposited in the repositories.
Conclusion. The study contributes to the discussion about the sustainability of research publications and data in the repositories by pointing to the potential difficulties involved for long-term preservation and access when there is little focus on and awareness of open file formats.