@@ -102,16 +102,17 @@
   (define file (or (assoc 'filename attrs) ""))
   (define codeblock `(pre [[class "code"]] (code ,@elems)))
   (cond [(string>? file "") `(@ (div [[class "listing-filename"]] 128196 " " ,file) ,codeblock)]
         [else codeblock]))
 
-(define (html-index . elems)
-  `(a [[id ,(here-id (list "_idx-" (uri-encode (car elems))))]
-       [href ,(string-append "/keyword-index.html#" (uri-encode (string-downcase (car elems))))]
-       [data-index-entry ,(car elems)]
+(define (html-index attrs elems)
+  (define index-key (maybe-attr 'key attrs (tx-strs `(span ,@elems))))
+  `(a [[id ,(here-id (list "_idx-" (uri-encode index-key)))]
+       [href ,(string-append "/keyword-index.html#" (uri-encode (string-downcase index-key)))]
+       [data-index-entry ,index-key]
        [class "index-link"]]
-      ,@(cdr elems)))
+      ,@elems))
 
 (define (html-say . elems)
   `(@ (dt ,(car elems) (span [[class "x"]] ": ")) (dd ,@(cdr elems))))
 
 (define (html-verse attrs elems)