diff --git a/.gitignore b/.gitignore
index f2e56d3..6cd6664 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
 /target
 Cargo.lock
 target/
+
+# stray build dir (not source)
+/src/CUBELinux-build/
diff --git a/cubesys/src/notes.rs b/cubesys/src/notes.rs
index 13cee15..69df585 100644
--- a/cubesys/src/notes.rs
+++ b/cubesys/src/notes.rs
@@ -486,6 +486,24 @@ pub fn note_command(store: &ConcurrentStore, line: &str) -> Result<String, Strin
             let notes = search_notes(store, &pos, Some(&f));
             Ok(format!("search '{pos}':\n{}", format_notes(&notes)))
         }
+        "tag" => {
+            let mut parts = rest.split_whitespace();
+            let cs = parts.next().unwrap_or("");
+            let cat = parts.next().unwrap_or("");
+            let coord = crate::commands::parse_coord(cs)
+                .ok_or_else(|| format!("bad coordinate '{cs}' (want C.Z.Y.X)"))?;
+            if cat.is_empty() {
+                return Err("note tag needs <coord> <cat>".to_string());
+            }
+            match store.get_record(&coord) {
+                Some((mut header, body)) => {
+                    header.doc_type = Some(format!("{NOTE_DOC_TYPE}:{cat}"));
+                    store.put_record(coord, &header, &body);
+                    Ok(format!("note {} tagged {cat}", coord_str(coord)))
+                }
+                None => Ok(format!("note {} -> (no note)", coord_str(coord))),
+            }
+        }
         "show" => {
             let cs = rest.trim();
             let coord = crate::commands::parse_coord(cs)