From the "About Factoid Prosopography" website (accessed 2019-08-28):
Factoid Prosopography is an approach to representing prosopographical research that centres on the idea of the “factoid”. It is an approach that had its beginnings in the Centre for Computing in the Humanities at King’s College London (now Department of Digital Humanities) in the mid 1990s, but which has continued to be refined and modified there since then through a number of historically independent prosopographies. Furthermore, factoid (or at least factoid-like) thinking has been taken up in varying degrees by other individuals and projects. If judged by the number of digital historians who seem interested in it, the idea of factoids in prosopography has proven to be a useful one for thinking about data-oriented, highly structured, prosopography. However, it does seem that beyond a general sense of what a factoid might be there has been little agreement outside of CCH/DDH about what a prosopography in the factoid style should actually be like.