diff --git a/collects/scribble/manual.ss b/collects/scribble/manual.ss
index 68d9fa09..861b4424 100644
--- a/collects/scribble/manual.ss
+++ b/collects/scribble/manual.ss
@@ -1885,6 +1885,12 @@
                                        (cond
                                         [(string? i)
                                          (cond
+                                          [(regexp-match #px"^(.*)_([a-zA-Z0-9]+)(.*)$" i)
+                                           => (lambda (m)
+                                                (append (loop (cadr m))
+                                                        (list (make-element 'subscript
+                                                                            (loop (caddr m))))
+                                                        (loop (cadddr m))))]
                                           [(regexp-match #px"^(.*)([()0-9{}\\[\\]])(.*)$" i)
                                            => (lambda (m)
                                                 (append (loop (cadr m))