DTDs

<!ENTITY % plistObject 
  "(array | data | date | dict | real | integer | string | true | false )" >
<!ELEMENT plist %plistObject;>
<!ATTLIST plist version CDATA "1.0" >

<!-- Collections -->
<!ELEMENT array (%plistObject;)*>
<!ELEMENT dict (key, %plistObject;)*>
<!ELEMENT key (#PCDATA)>

<!--- Primitive types -->
<!ELEMENT string (#PCDATA)>
<!ELEMENT data (#PCDATA)> <!-- Contents interpreted as Base-64 encoded -->
<!ELEMENT date (#PCDATA)> <!-- Contents should conform to a subset of ISO 8601 
                               (in particular, YYYY '-' MM '-' DD 'T' HH ':' MM ':' SS 'Z'.  
                               Smaller units may be omitted with a loss of precision) -->

<!-- Numerical primitives -->
<!ELEMENT true EMPTY>  <!-- Boolean constant true -->
<!ELEMENT false EMPTY> <!-- Boolean constant false -->
<!ELEMENT real (#PCDATA)> <!-- Contents should represent a 
                               floating point number matching 
                               ("+" | "-")? d+ ("."d*)? ("E" ("+" | "-") d+)? 
                               where d is a digit 0-9.  -->
<!ELEMENT integer (#PCDATA)> <!-- Contents should represent a (possibly signed) 
                                  integer number in base 10 -->