 Formal studies of facts are scarce. And they are also heterogeneous, both in form and in content. In form insofar as they are formulated in languages of various kinds, which vary greatly in expressive power. And in content, not only because of the variety of views on given issues, but also because the kind of issues dealt with varies greatly. This makes it difficult to present these theories within a uniform framework. We are going to choose a specific framework, present, within that framework, (some of) the options a fact-theorist may wish to adopt, study their relationships, and give references in due course to indicate where in the resulting space of possible theories various accounts, formal and non-formal, are to be located. Our framework is significantly distinct from many of those which are used in the literature. So it should be kept in mind that in attributing this or that view to an author, what we will say is often not to be understood literally: when it is not, what we really attribute to the author is something which, translated into our framework, is what we literally attribute to her.