The introduction of ROR's minimum viable product for unique institutional identifiers provides a platform on which many of us hope to build. We have been exploring ways to implement institutional identifiers down to the department level for RORs. A simple parent/child model would be the easiest approach, but relationships among and between organizations is both complex and dynamic. For the use case of departmental bibliographies, it may be that this is enough and is a reasonable first step as we explore expanding institutional relationships in more detail.