<!DOCTYPE doc [
<!ELEMENT doc - - (placrule)>
<!ELEMENT placrule - O EMPTY>
<!ATTLIST placrule
          a (a01|a02|a03|a04|a05) #IMPLIED
          b (a06|a07|a08) #IMPLIED
          c (a09|a10|a11|a12|a13|a14|a15|a16|a17|a18|a19) #IMPLIED
          d (a20|a21) #IMPLIED
          e (a22|a23|a24|a25|a26|a27|a28|a29|a30|a31|a32) #IMPLIED
          f (a33|a34|a35) #IMPLIED
>
]>
