diff --git a/data/structures/_types.yml b/data/structures/_types.yml
index d31d8c3..b2e1054 100644
--- a/data/structures/_types.yml
+++ b/data/structures/_types.yml
@@ -78,6 +78,11 @@ types:
       download:
       icon:
       force:
+      # no inherited defaults of their own: cue and tab are declared optional
+      # without a default in _arguments.yml, so an absent value stays absent and
+      # the consuming partial applies main.externalLinks.cue / .tab
+      cue:
+      tab:
       # no inherited defaults: downstream partials layer their own (download.yml
       # sets outline/order; section context supplies order) as in v5
       order: { default: }