diff --git a/book/source/04-certificates.md b/book/source/04-certificates.md
index 0ce7df8..41c7a83 100644
--- a/book/source/04-certificates.md
+++ b/book/source/04-certificates.md
@@ -480,12 +480,16 @@ write, link to chapter 9
 Wiktor suggests to check: https://blogs.gentoo.org/mgorny/2018/08/13/openpgp-key-expiration-is-not-a-security-measure/ for important material
 ```
 
+(dks-puid)=
 ### Metadata about the primary key: In Direct Key Signature vs. in Primary User ID, in v4 and v6
 
 ```{admonition} TODO
 :class: warning
 
-write
+i think crypto-refresh suggests that the direct key signature should hold the default preferences?
+we might need to write a more nuanced text here, about how DKS and primary user id interact in v6, and mention the differences to v4? 
+
+the primary User ID can also specify metadata about the primary key
 ```
 
 ### Metadata leak of Social Graph