Current tag models do not fully take into account the rich and diverse nature of tags. Each model makes different partial assumptions as to the definition and attributes a tag should receive. In this paper we propose an ontology, NiceTag, whose primitives are "tag actions" modeled with RDF named graphs. This mechanism allows us to type, describe and thus ensure the traceability of each single act of tagging. Our named graphs contain at least a resource linked to a "sign", which can be any resource reachable on the Web (an ontology concept, an image, etc.). The resource, the sign and the link between them are the three components of the acts of tagging that we want to explicitly represent as social actions, akin to speech acts. The purpose of our model is threefold. First, to be able to describe acts of tagging in a very precise and general manner, consistent with the principles behind the architecture of the Web. To reconcile and bridge existing tag models (Newman ontology, Tagont, ES, SCOT, SIOC, CommonTag, MOAT, NAO). And finally, to propose a viable way to reify and represent the intention behind an act of tagging and leverage its semantics.