ABAC is an attribute-based access control system that uses attributes on objects to determine access permissions. It allows for defining arbitrary sets of information to use for making decisions, unlike role-based access control which defines roles based on predefined categories. ABAC can be combined with ReBAC to provide the benefits of both approaches. SpiceDB has introduced the concept of caveats, which allows combining the flexibility of ABAC with the power and efficiency of ReBAC by applying ABAC-like policy to specific subsets of permissions decisions. This approach enables leveraging the benefits of attribute-based decision making with the efficiency of parallelization, structural graph walking, and event aggressive caching in SpiceDB.