This document describes an Under-Specified FEC Scheme that can be used with the broad class of Low Density Parity Check (LDPC) codes and their application to the reliable delivery of objects on packet erasure channels. Additionally, this document describes the LDPC-Staircase and LDPC-Triangle Forward Error correction codes, two instances of the LDPC FEC Scheme, in a way that enables fully inter-operable implementations. The LDPC codes belong to the class of large block FEC codes, as defined in RFC3453, which enables them to efficiently encode/decode large objects, in a single block. They also enable a receiver to recover the k source symbols from any set of a little bit more than k encoding symbols.