const char * const unique = ((struct MarkdownToHtml*)opaque)->unique.c;
  assert( nUsed >= 0 );
  /* expect BUGs if the following yields compiler warnings */

  if( iMark < 0 ){                     /* misreferences */
    assert( iMark == -1 );
    if( !nUsed ) return;
    BLOB_APPEND_LITERAL(ob,"<li class='misreferences'>"
                              "<sup class='footnote-backrefs'>");
    BLOB_APPEND_LITERAL(ob,"<li class='fn-misreference'>"
                              "<sup class='fn-backrefs'>");
    if( nUsed == 1 ){
      blob_appendf(ob,"<a id='misreference%s-a' "
                      "href='#misref%s-a'>^</a>", unique, unique);
    }else{
      int i;
      blob_append_char(ob, '^');
      for(i=0; i<nUsed && i<26; i++){
        const int c = i + (unsigned)'a';
        blob_appendf(ob," <a id='misreference%s-%c' "
              "href='#misref%s-%c'>%c</a>", unique,c, unique,c, c);
      }
      if( i < nUsed ) BLOB_APPEND_LITERAL(ob," &hellip;");
    }
    BLOB_APPEND_LITERAL(ob,"</sup>\nMisreference: use of undefined label.");
    BLOB_APPEND_LITERAL(ob,"</sup>\n<span>Misreference</span>");

  }else if( nUsed ){                   /* a regular footnote */
    char pos[24];
    const char *join = "";
    #define _joined_footnote_indicator "<ul class='fn-joined'>"
    #define _jfi_sz (sizeof(_joined_footnote_indicator)-1)
    assert( text );
    assert( blob_size(text) );
    if( blob_size(text)>=_jfi_sz &&
       !memcmp(blob_buffer(text),_joined_footnote_indicator,_jfi_sz)){
      join = "fn-joined ";

    }
    memset(pos,0,24);
    sprintf(pos, "%s-%i", unique, iMark);

    blob_appendf(ob, "<li id='footnote%s'>", pos);
    BLOB_APPEND_LITERAL(ob,"<sup class='footnote-backrefs'>");
    if( nUsed <= 1 ){
    blob_appendf(ob, "<li id='footnote%s' class='%s", pos, join);

    if( nUsed == 1 ){
      BLOB_APPEND_LITERAL(ob, "fn-monoref'><sup class='fn-backrefs'>");
      blob_appendf(ob,"<a id='footnote%s-a' "
                       "href='#noteref%s-a'>^</a>", pos, pos);
    }else{
      int i;
      blob_append_char(ob, '^');
      BLOB_APPEND_LITERAL(ob, "fn-polyref'><sup class='fn-backrefs'>^");
      for(i=0; i<nUsed && i<26; i++){
        const int c = i + (unsigned)'a';
        blob_appendf(ob," <a id='footnote%s-%c'"
                         " href='#noteref%s-%c'>%c</a>", pos,c, pos,c, c);
      }
      /* It's unlikely that so many backrefs will be usefull */
      /* but maybe for some machine generated documents... */
      for(; i<nUsed && i<676; i++){
        const bitfield64_t l = to_base26(i,0);
        blob_appendf(ob," <a id='footnote%s-%s'"
                         " href='#noteref%s-%s'>%s</a>",
                         pos,l.c, pos,l.c, l.c);
      }
      if( i < nUsed ) BLOB_APPEND_LITERAL(ob," &hellip;");
    }
    BLOB_APPEND_LITERAL(ob,"</sup>\n");
    if( join[0] ){
      BLOB_APPEND_LITERAL(ob,"<sup class='fn-joined'></sup><ul>");
      blob_append(ob,blob_buffer(text)+_jfi_sz,blob_size(text)-_jfi_sz);
    }else{
    BLOB_APPEND_BLOB(ob, text);
      BLOB_APPEND_BLOB(ob, text);
    }
    #undef _joined_footnote_indicator
    #undef _jfi_sz
  }else{
    /* a footnote was defined but wasn't used */
    /* make.footnote_item() invocations should pass args accordingly */
    const struct Blob * id = text-1;
    assert( text );
    assert( blob_size(text) );
    assert( blob_size(id) );
    BLOB_APPEND_LITERAL(ob,"<li class='unreferenced'>\n[^&nbsp;<code>");
    BLOB_APPEND_LITERAL(ob,"<li class='fn-unreferenced'>\n[^&nbsp;<code>");
    html_escape(ob, blob_buffer(id), blob_size(id));
    BLOB_APPEND_LITERAL(ob, "</code>&nbsp;] "
    BLOB_APPEND_LITERAL(ob, "</code>&nbsp;]<i></i>\n"
        "<i>was defined but is not referenced</i>\n"
        "<pre><code class='language-markdown'>");
    html_escape(ob, blob_buffer(text), blob_size(text));
    BLOB_APPEND_LITERAL(ob,"</code></pre>");
  }
  BLOB_APPEND_LITERAL(ob, "\n</li>\n");
}
static void html_footnotes(