Update parked-domain-how-to.md

parked-domain-how-to.md

@@ -1,11 +1,11 @@
 - [Introduction](#introduction)
 - [What is a parked domain?](#what-is-a-parked-domain-)
-  * [Domain without e-mail](#domain-without-e-mail)
-    + [Null MX](#null-mx)
-    + [DMARC](#dmarc)
-    + [DKIM](#dkim)
-    + [SPF](#spf)
-  * [Domain without a website](#domain-without-a-website)
+- [Domain without e-mail](#domain-without-e-mail)
+  * [Null MX](#null-mx)
+  * [DMARC](#dmarc)
+  * [DKIM](#dkim)
+  * [SPF](#spf)
+- [Domain without a website](#domain-without-a-website)
 
 <small><i><a href='http://ecotrust-canada.github.io/markdown-toc/'>Table of contents generated with markdown-toc</a></i></small>
 
@@ -15,30 +15,32 @@ This how-to is created by the Dutch Internet Standards Platform (the organizatio
 # 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
+# Domain without e-mail
 If a domain is not using e-mail it is recommended to use the following settings.
 
-### Null MX
+## 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
 When used with a wildcard selector, setting an empty public key indicates that all previously used keys are revoked and must be considered unreliable. The owner of a domain can also use this to explicitly signal that a domain is not configured to use e-mail. See our [DKIM how-to](https://github.com/internetstandards/toolbox-wiki/blob/master/DKIM-how-to.md) for more information. 
 
 `*._domainkey IN TXT "v=DKIM1; p="`
 
-### SPF
+## SPF
 Set an an empty policy (not mentioning any ip-adresses or hostnames which are allowed to send mail) and a hard fail.
 
 `example.nl IN TXT "v=spf1 –all"`
  
-## Domain without a website
+# Domain without a website
+Apply the following settings to domains not using 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 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.