diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 7379b04ad16..4bc91fc4030 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -51,6 +51,11 @@ pub struct ItemSummary {
     pub crate_id: u32,
     /// The list of path components for the fully qualified path of this item (e.g.
     /// `["std", "io", "lazy", "Lazy"]` for `std::io::lazy::Lazy`).
+    ///
+    /// Note that items can appear in multiple paths, and the one chosen is implementation
+    /// defined. Currenty, this is the full path to where the item was defined. Eg
+    /// [`String`] is currently `["alloc", "string", "String"]` and [`HashMap`] is
+    /// `["std", "collections", "hash", "map", "HashMap"]`, but this is subject to change.
     pub path: Vec<String>,
     /// Whether this item is a struct, trait, macro, etc.
     pub kind: ItemKind,