[2] RFC 1014 - XDR: External Data Representation standard, 2023-07-03T07:16:17.000Z https://datatracker.ietf.org/doc/html/rfc1014#section-5

[3] RFC 1832 - XDR: External Data Representation Standard, 2023-07-03T07:17:04.000Z https://datatracker.ietf.org/doc/html/rfc1832#section-5.1

[1] RFC 4506: XDR: External Data Representation Standard, 2023-07-03T07:03:25.000Z, 2023-07-03T07:13:21.225Z https://www.rfc-editor.org/rfc/rfc4506.html#section-6.1

an extended Back-Naur Form notation