diff --git a/index.bs b/index.bs
index 747c9c2c..5ded410c 100644
--- a/index.bs
+++ b/index.bs
@@ -544,6 +544,32 @@ i.e. consistency within CSS.
There is also a separate section on naming consistency.
+
Follow guidance from feature specifications
+
+When using a feature,
+follow guidance in the specification for that feature.
+
+Specifications for features
+that will be used by other specifications
+should include guidance for using those features.
+This ensures that the feature is used correctly
+and consistently
+throughout the platform.
+
+An incomplete list of such guidance follows:
+
+* [[encoding#specification-hooks|Encoding]]
+* [[fetch#fetch-elsewhere|Fetch]]
+* [[hr-time#sec-tools|Time]]
+* [[url#url-apis-elsewhere|URLs]]
+* [[#using-http]]
+
+Consult with the relevant community
+when using their specification.
+This informs that community about new usage
+and creates opportunities for improvements
+to both the using and used specifications.
+
New features should be detectable
Provide a way for authors to programmatically detect