diff --git a/Dynamic-filtering:-quick-guide.md b/Dynamic-filtering:-quick-guide.md
index a8e9192..ccaf25d 100644
--- a/Dynamic-filtering:-quick-guide.md
+++ b/Dynamic-filtering:-quick-guide.md
@@ -12,6 +12,8 @@ As you can see, you can create dynamic filtering rules for object types, or host
 
 The color of an entry indicate whether all requests were blocked (reddish), all requests were allowed (greenish), or some were blocked some were allowed (yellowish).
 
+In bold, domain names. Domains are hostnames, but hostnames are not domains from µBlock's point of view: domains are extracted as per [Mozilla Public Suffix list](https://publicsuffix.org/).
+
 Second column: global dynamic filtering rules, i.e. whatever rule appears in this column applies everywhere, on all sites:
 
 ![figure 3](https://raw.githubusercontent.com/gorhill/uBlock/master/doc/img/df-qg-03.png)