diff --git a/DMARC-how-to.md b/DMARC-how-to.md
index 2222a3b..a9755cd 100644
--- a/DMARC-how-to.md
+++ b/DMARC-how-to.md
@@ -18,7 +18,7 @@ DMARC addresses this problem and enables the owner of a domain to take explicit
 * Interoperabily issues: https://tools.ietf.org/html/rfc7960
 * DMARC does not require both DKIM or SPF. But implementation of both is strongly advised.
 * DMARC is about aligning the DKIM and/or SPF domain with the organizational domain in the From header.
-* Parked domain: “DMARC p=reject”. Make sure to include rua and ruf addresses, since this allows monitoring of possible abuse attempts. Implement additional records (SPF, DKIM, NullMX) if possible, see also: https://www.m3aawg.org/sites/default/files/m3aawg_parked_domains_bp-2015-12.pdf
+* Parked domain: “DMARC p=reject”. Make sure to include rua and ruf addresses, since this allows monitoring of possible abuse attempts. Implement additional records (SPF, DKIM, NullMX) if possible, see also our [Parked domain how-to](https://github.com/internetstandards/toolbox-wiki/blob/master/parked-domain-how-to.md).
 * RFC 7489 [states](https://tools.ietf.org/html/rfc7489#section-6.4) that the tags dmarc-version ("v=") and dmarc-request ("p=") should be on the first and second position of the DMARC record. The order of the other tags does not matter: "components other than dmarc-version and dmarc-request may appear in any order".
 * [Errata 5440 of RFC 7489](https://www.rfc-editor.org/errata_search.php?rfc=7489) states that a semicolon should be included in the DMARC version tag. Correct: "v=DMARC1;". Incorrect: "v=DMARC1". 
 * When using office 365, the forwarding of calendar appointments from a DMARC projected domain fails. This is a known issue. Read more on the [Office 365 UserVoice forum](https://office365.uservoice.com/forums/264636-general/suggestions/34012756-forwarding-of-calendar-appointments-from-a-dmarc-p) and don't forget to submit your vote!