diff --git a/docs/faq.rst b/docs/faq.rst
index dc6097c8..3c2ac972 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -112,6 +112,11 @@ If you want to include metadata in templates outside the article context (e.g.,
 
     {% if article and article.modified %}
 
+.. note::
+
+    Because the colon symbol (``:``) is used as a separator, be aware that
+    metadata field names *containing* a colon will probably not work.
+
 How do I make my output folder structure identical to my content hierarchy?
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