The World Wide Web has evolved into a distributed network of web applications facilitating the publication of information on a large scale. Judging whether such information can be trusted is a difficult task for humans, often leading to blind trust. In this paper we present a model and the corresponding veracity ontology which allows trust to be placed in web content by web agents. Our approach differs from current work by allowing the trustworthiness of web content to be securely distributed across arbitrary domains and asserted through the provision of machine-readable proofs (i.e. by citing another piece of information, or stating the credentials of the user/agent). We provide a detailed scenario as motivation for our work and demonstrate how the ontology can be used.