anchor.diff:       | [] -> (List.rev items, [])
        | (i, text: string)::lines ->
          if text.Length = 0
  -          || List.exists text.StartsWith ["#"; "// "; "////"; "open "] then
  +          || List.exists text.StartsWith ["#"; "// "; "open "] then
            outside indent path items docs attrs lines
          elif i <= indent then
            (List.rev items, (i, text)::lines)
  +       elif text.StartsWith "////" then
  +         let item = {Doc = [text.Substring 4]
  +                     Attr = []
  +                     Kind = Some "spacer"
  +                     Id = None
  +                     Path = []
  +                     Indent = i
  +                     Tokens = []
  +                     Body = []}
  +         outside indent path (item::items) [] [] lines
          elif text.StartsWith "///" then
            outside indent path items (text.Substring 3::docs) attrs lines
          elif text.StartsWith "//# " then
  
positive.code:   let indent = max (item.Indent - drop) 0
    let prefix = String.replicate indent " "
    if item.Kind = Some "header" then
      fprintf wr "%s<h3>%s</h3>\n" prefix <| List.head item.Doc
    else
      item.Attr
      |> Seq.iter ^ fun attr ->
           fprintf wr "%s" prefix
  
negative.code:               <html>\n"
    fprintf wr "<head>\n"
    fprintf wr "<title>%s Library Reference</title>\n" title
    fprintfn wr "%s" """<style>
  pre {
    border: 1px solid #e0e0e0;
    border-radius: 3px;
    padding: 5px;
    background: #f7f7f7;
    line-height: 160%;
    font-family: "Lucida Console", Monaco, monospace;
    font-size: 72%;
  }
  code {
    border: 1px solid #e0e0e0;
    border-radius: 3px;
    padding: 2px;
    background: #f7f7f7;
    line-height: 160%;
    font-family: "Lucida Console", Monaco, monospace;
    font-size: 72%;
  }
  span.h3 {
    display: inline-block;
    font-weight: bold;
    font-size: 1.17em;
    font-family: inherit;
    margin: 0.75em 0em 0.5em 0em;
  }
  span.spacing {
    display: inherit;
    margin: 0.5em 0em 0.5em 0em;
  }
  div.nested {
    padding-left: 1.5em;
  }
  a {
    text-decoration: none;
    font-weight: bold;
  }
  </style>"""
    fprintf wr "</head>\n"
    fprintf wr "<body><table width=\"80%%\" align=\"center\"><tr><td>\n"
    fprintf wr "<h1>%s Library Reference</h1>\n" title
    fprintf wr "<h2>Synopsis</h2>\n"
    fprintf wr "<pre>"
    printTokens wr id2items " " (Some "dec") "def" model.Id model.Path model.Kind model.Tokens
    fprintf wr "\n"
    model.Body
    |> Seq.filter (isObsolete >> not)
    |> Seq.iter ^ printSummary wr id2items true (Some "dec") "def" 0
    fprintf wr "</pre>\n"
    fprintf wr "<h2>Description</h2>\n"
    printDescription wr id2items model
    fprintf wr "</td></tr></table></body>\n"
  