Primero y antes que nada, debemos de saber qué es el Registro Federal de Contribuyentes mejor conocido por todo como RFC, que en términos directos es un identificador en el ámbito financiero de México ...
42 Pregunta: ¿Cómo puedo verificar que el formato de un RFC mexicano sea válido? ¿Qué es el RFC? El Registro Federal de Contribuyentes (RFC) es una clave única que requiere toda persona física o moral en México para realizar cualquier actividad económica lícita. Es el código tributario de personas y empresas expedido por el SAT.
Pretty much, yes - RFC 3339 is listed as a profile of ISO 8601. The RFC also has some small, subtle differences. For example truncated representations of years with only two digits are not allowed -- RFC 3339 requires 4-digit years, and the RFC only allows a period character to be used as the decimal point for fractional seconds.
Parsing RFC-3339 / ISO-8601 date-time string in Go Asked 11 years, 7 months ago Modified 4 years, 2 months ago Viewed 413k times
6 Regarding the syntax of hostnames, answers to questions like this often refer to RFC 1123 and RFC 952, but fail to mention RFC 921 which seems to place additional restrictions on hostnames. There are probably a bunch of later RFCs about the DNS (and IDN) which cover constraints on hostnames handled by the DNS.
Which RFCs specify the syntax of hostnames and constraints on DNS ...
It is the responsibility of the sender of the email to stay within the RFC specified limits. Mail servers themselves can be lenient and happily accept things that exceed those limits, or they can be strict and reject this. It is not the responsibility of the mail server to rewrite your email to be within the requirements of the various SMTP and mail-related RFCs. So, you - as the sender of the ...