API v0.5/DTD

 <!ELEMENT osm ((node|relation|way)*)>
 <!ATTLIST osm version   (0.5) #REQUIRED>
 <!ATTLIST osm generator CDATA #REQUIRED>

<!ELEMENT node (tag*)>
<!ATTLIST node id        CDATA #REQUIRED>
<!ATTLIST node lat       CDATA #REQUIRED>
<!ATTLIST node lon       CDATA #REQUIRED>
<!ATTLIST node visible   CDATA #IMPLIED>
<!ATTLIST node user      CDATA #IMPLIED>
<!ATTLIST node timestamp CDATA #IMPLIED>

<!ELEMENT way (tag*,nd,tag*,nd,(tag|nd)*)>
<!ATTLIST way id        CDATA #REQUIRED>
<!ATTLIST way visible   CDATA #IMPLIED>
<!ATTLIST way user      CDATA #IMPLIED>
<!ATTLIST way timestamp CDATA #IMPLIED>

<!ELEMENT nd EMPTY>
<!ATTLIST nd ref         CDATA #REQUIRED>

<!ELEMENT relation ((tag|member)*)>
<!ATTLIST relation id        CDATA #REQUIRED>
<!ATTLIST relation visible   CDATA #IMPLIED>
<!ATTLIST relation user      CDATA #IMPLIED>
<!ATTLIST relation timestamp CDATA #IMPLIED>

<!ELEMENT member EMPTY>
<!ATTLIST member type (way|node|relation) #REQUIRED>
<!ATTLIST member ref  CDATA  #REQUIRED>
<!ATTLIST member role CDATA  #IMPLIED>

<!ELEMENT tag EMPTY>
<!ATTLIST tag  k         CDATA #REQUIRED>
<!ATTLIST tag  v         CDATA #REQUIRED>