diff --git a/docs/custom-props/introduction.md b/docs/custom-props/introduction.md
index 74f017eb..c6c064dd 100644
--- a/docs/custom-props/introduction.md
+++ b/docs/custom-props/introduction.md
@@ -35,6 +35,8 @@ Note that you must ensure that no personally identifiable information (PII) is s
 * IP addresses
 * pseudonymous cookie IDs, advertising IDs or other pseudonymous end user identifiers
 
+If you're confused whether the information you're sending to us qualifies as PII, look at the [explanations and examples](https://plausible.io/blog/pii-examples) in our guide.
+
 ## `(none)` values
 
 Plausible will display `(none)` in your dashboard when you send a custom property key with no value, or `null`/`undefined` as a value. Also, when you send one event with a property (e.g. `author`) and another event with the same name, but without the `author` property, then you will also see the `(none)` value because the property has not been sent with every event.