Governing the life cycle of data on the web is a challenging issue for organisations and users. Data is distributed under
certain policies that determine what actions are allowed and in which circumstances. Assessing what policies propagate
to the output of a process is one crucial problem. Having a description of policies and data flow steps implies a huge number of propagation rules to be specified and computed (number of policies times number of actions). In this paper
we provide a method to obtain an abstraction that allows to reduce the number of rules significantly. We use the Datanode
ontology, a hierarchical organisation of the possible relations between data objects, to compact the knowledge base
to a set of more abstract rules. After giving a definition of Policy Propagation Rule, we show (1) a methodology to
abstract policy propagation rules based on an ontology, (2) how effective this methodology is when using the Datanode
ontology, (3) how this ontology can evolve in order to better represent the behaviour of policy propagation rules.
