RFC6052 specifies the algorithmic translation of an IPv6 address to a corresponding IPv4 address, and vice versa. In particular, RFC6052 specifies the address format to build IPv4-converted and IPv4- translatable IPv6 addresses. In order to be deployed in the context of stateless 4/6 solutions, RFC6052 should be updated so that IPv4- embedded IPv6 addresses convey the port information. This document identifies a set of requirements to be taken into account when updating RFC6052 for that purpose. A companion effort, document at [I-D.bsd-softwire-stateless-port-index-analysis], is required to converge on one or a set of algorithms to be used by all stateless solutions.