diff --git a/content/conf.py b/content/conf.py
index 6c265b4..9359ce0 100644
--- a/content/conf.py
+++ b/content/conf.py
@@ -54,6 +54,11 @@
 #nb_execution_mode = "force"
 nb_execution_mode = "cache"
 
+# https://myst-parser.readthedocs.io/en/latest/syntax/optional.html
+myst_enable_extensions = [
+    "colon_fence",
+]
+
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']