code: func IsValidPortName(port string) bool {
  	if len(port) < 1 || len(port) > 15 {
  		return false
  	}
  	if doubleHyphensRegexp.MatchString(port) {
  		return false
  	}
  	if identifierNoHyphensBeginEndRegexp.MatchString(port) && atLeastOneLetterRegexp.MatchString(port) {
  		return true
  	}
  	return false
  }
docs: // IsValidPortName check that the argument is valid syntax. It must be non empty and no more than 15 characters long
  // It must contains at least one letter [a-z] and it must contains only [a-z0-9-].
  // Hypens ('-') cannot be leading or trailing character of the string and cannot be adjacent to other hyphens.
  // Although RFC 6335 allows upper and lower case characters but case is ignored for comparison purposes: (HTTP
  // and http denote the same service).