Updated information for parked domains

parked-domain-how-to.md

@@ -1,26 +1,32 @@
 # Introduction
 This how-to is created by the Dutch Internet Standards Platform (the organization behind [internet.nl](https://internet.nl)) and is meant to provide practical information and guidance on explicitly configuring a parked domain not to use e-mail.
 
-# Null MX
+# What is a parked domain?
+[Domain parking](https://en.wikipedia.org/wiki/Domain_parking) is the registration of an Internet domain name without that domain being associated with any services such as e-mail or a website. 
+
+## Domain without e-mail
+If a domain is not using e-mail it is recommended to use the following settings.
+
+### Null MX
 Explicitly configure an 'empty' MX record according to [RFC7505 ](https://tools.ietf.org/html/rfc7505). 
 
 `example.nl IN MX 0 .`
 
-# DMARC
+### DMARC
+Set DMARC policy to reject mails, but allow reporting to take place. This helps detecting activity related to your domain.
 
 `_dmarc IN TXT "v=DMARC1; p=reject; rua=mailto:rua@example.nl; ruf=mailto:ruf@example.nl`
 
-# DKIM
+### DKIM
 
-`selector._domainkey IN TXT "v=DKIM1; p="`
+`*._domainkey IN TXT "v=DKIM1; p="`
 
-# SPF
+### SPF
 
 `example.nl IN TXT "v=spf1 –all"`
-   
-# Other tips and tricks
+ 
+## Domain without a website
 * Don't use an A or AAAA record for parked domains.
-* Don't redirect from a parked domain to the used domain, since this encourages users to keep using the parked domain name.
-  * If a redirect is used, make sure to use the proper redirect order in order for HSTS headers to remain effective: 
+* Don't redirect from a parked domain to the used domain, since this encourages users to keep using the parked domain name. If a redirect is desirable, make sure to use the proper redirect order in order for HSTS headers to remain effective: 
     1. redirect from HTTP to HTTPS on the same (sub)domain.
     2. when using HTTPS, redirect to another (sub)domain.