This defines proposed new functionality of the FIO Protocol, which would allow FIO Domains to be mapped to DNS records.
The goal of DNS mappings would be to make them compatible with the existing DNS conventions, which expects the name to have the format of 'subdomain.domain.tld'.
Adding DNS mapping capabilities to the FCH would fail to achieve this goal and could potentially be confusing to users due to the FCH format which contains the '@' symbol, e.g. purse@alice. Therefore, this FIP proposes adding mapping capability to FIO Domains instead.
Furthermore, the FIO Protocol does not currently support the notion of sub-domains, or top level domains (TLDs). A .fio TLD could be appended by the integrating application to indicate that resolution request should be directed to the FIO Protocol. .fio TLD is not currently supported by ICANN and therefore there would not be any collisions with traditional DNS. Foundation for Interwallet Operability could consider funding the .fio TLD application with ICANN in the future once TLD applications resume. If Alternative DNS Roots, such as Handshake gain more global traction, those could be used instead. The concept of FIO sub-domains is not proposed in this FIP, but could be considered in the future.