diff --git a/data/json/itemgroups/corpses.json b/data/json/itemgroups/corpses.json
index 2b411f57d7060..1e0bb81964a83 100644
--- a/data/json/itemgroups/corpses.json
+++ b/data/json/itemgroups/corpses.json
@@ -508,6 +508,7 @@
   {
     "id": "corpses_all",
     "type": "item_group",
+    "//": "Used in the code for the biogas digester.",
     "items": [ { "group": "corpses" }, { "item": "corpse" } ]
   }
 ]