When the Trustlines Protocol was originally conceived, the first use case considered was that of a decentralized, immutable accounting system for netted IOU balances between trusted parties. The Trustlines Protocol is, however, now being developed to support a wider range of use cases, i.e., all those which can leverage networks of formal and informal trust-based relationships and want to build on a decentralized system. The Trustlines Foundation invites contributors to submit their analysis of potential use cases of the Trustlines Protocol.