Source: (?)  Apparently from 'The Digital Property Rights Language, Manual and Tutorial - XML Edition'
   Version 2.00, November 13, 1998.

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APPENDIX B.  GRAMMAR FOR THE DIGITAL PROPERTY LANGUAGE
This section collects together the complete DTD for the digital property language.

<!-- The work specification DTD -->

<?XML version="1.0" encoding="UTF-8"?>
<!ELEMENT Work (RightsVersion,
        WorkId?,
        Description?,
        Owner?,
        Parts?,
        Contents?,
        Copies?,
        Comment?,
        (RightsGroup | ReferencedRightsGroup)+
      )>

<!ELEMENT RightsVersion EMPTY>
<!ATTLIST RightsVersion version-id CDATA #REQUIRED>

<!ELEMENT WorkId EMPTY>
<!ATTLIST WorkId work-id CDATA #REQUIRED>

<!ELEMENT Description (#PCDATA)>

<!ELEMENT Owner (Certificate)>

<!ELEMENT Parts (WorkId+)>

<!ELEMENT Contents EMPTY>
<!ATTLIST Contents from CDATA #REQUIRED
                      to CDATA #REQUIRED>

<!-- If copy count is not specified, then "unlimited" is assumed. -->
<!ELEMENT Copies EMPTY>
<!ATTLIST Copies copy-count CDATA #IMPLIED>

<!ELEMENT Comment (#PCDATA)>

<!-- ********* Rights Group List Started ************* -->
<!ELEMENT RightsGroup (Comment?, Bundle?, RightsList)>
<!ATTLIST RightsGroup group-name CDATA #REQUIRED>

<!ELEMENT ReferencedRightsGroup (Comment?, Bundle?, RightsList)>
<!ATTLIST ReferencedRightsGroup group-name CDATA #REQUIRED>

<!ELEMENT Bundle (Comment?, Time?, Access?, BundleFee?, Watermark?)>

<!-- ********* Rights List Started ************* -->

<!ELEMENT RightsList (  (Copy | Transfer | Loan |
                         Play | Print | Export |
                         Edit | Extract | Embed |
                         Backup | Restore | Verify | Folder | Directory | Delete |
                         Install | Uninstall)+
                     )>

<!ELEMENT Copy (NextCopyRights?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Transfer (NextCopyRights?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Loan (RemainingRights?, NextCopyRights?, Comment?, Time?, Access?, Fee?)>

<!ELEMENT Play (Player?, Watermark?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Print (Printer?, Watermark?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Export (Repository?, Comment?, Time?, Access?, Fee?)>

<!ELEMENT Edit (Editor?, NextCopyRights?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Extract (Editor?, NextCopyRights?, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Embed (Editor?, NextCopyRights?, Comment?, Time?, Access?, Fee?)>

<!ELEMENT Backup (BackupCopyRights, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Restore (Comment?, Time?, Access?, Fee?)>

<!ELEMENT Verify (Verifier, Comment?, Time?, Access?, Fee?)>
<!ELEMENT Folder (Comment?, Time?, Access?, Fee?)>
<!ELEMENT Directory (Comment?, Time?, Access?, Fee?)>
<!ELEMENT Delete (Comment?, Time?, Access?, Fee?)>

<!ELEMENT Install (Comment?, Time?, Access?, Fee?)>
<!ELEMENT Uninstall (Comment?, Time?, Access?, Fee?)>

<!ELEMENT NextCopyRights (RightsToAdd | RightsToDelete)>

<!ELEMENT RemainingRights EMPTY>
<!ATTLIST RemainingRights group-name CDATA #REQUIRED>

<!ELEMENT RightsToAdd EMPTY>
<!ATTLIST RightsToAdd group-name CDATA #REQUIRED>

<!ELEMENT RightsToDelete EMPTY>
<!ATTLIST RightsToDelete group-name CDATA #REQUIRED>

<!ELEMENT BackupCopyRights EMPTY>
<!ATTLIST BackupCopyRights group-name CDATA #REQUIRED>

<!ELEMENT Player (Certificate+)>
<!ELEMENT Printer (Certificate+)>
<!ELEMENT Repository (Certificate+)>
<!ELEMENT Editor(Certificate+)>
<!ELEMENT Verifier(Certificate+)>

<!-- ********* Rights List Ended ************* -->

<!-- ********* Rights Group List Ended ************* -->

<!--  ********* Time Started ************* -->

<!ENTITY % moment "yyyy CDATA #IMPLIED
                   mm CDATA #IMPLIED
                   dd CDATA #IMPLIED
                   hrs CDATA #IMPLIED
                   min CDATA #IMPLIED
                   sec CDATA #IMPLIED">

<!ENTITY % interval "years CDATA #IMPLIED
                 months CDATA #IMPLIED
                 days CDATA #IMPLIED
                 hours CDATA #IMPLIED
                 minutes CDATA #IMPLIED
                 seconds CDATA #IMPLIED">

<!ELEMENT Time ((From | Interval | Metered)?, Until)>

<!ELEMENT From EMPTY>
<!ATTLIST From %moment;>

<!ELEMENT Interval EMPTY>
<!ATTLIST Interval %interval;> 

<!ELEMENT Metered EMPTY>
<!ATTLIST Metered %interval;>

<!ELEMENT Until EMPTY>
<!ATTLIST Until %moment;>

<!-- ********* Time Ended ************* -->

<!--  ********* Fee Started ************* -->
<!ELEMENT Fee (Ticket | Monetary)>
<!ELEMENT Monetary ((PerUse | MeteredFee | BestPriceUnder | CallForPrice | Markup),
                     Min?,
                     Max?,
                     Account
                   )>

<!ELEMENT Ticket (Authority, Type)>

<!-- The only difference  from Fee is that Monetary type is also optional here-->
<!ELEMENT BundleFee (Ticket | BundleMonetary)>
<!ELEMENT BundleMonetary ((PerUse | MeteredFee | BestPriceUnder | CallForPrice | Markup)?,
                     Min?,
                     Max?,
                     Account
                    )>

<!ELEMENT Authority EMPTY>
<!ATTLIST Authority authority-id CDATA #REQUIRED>

<!ELEMENT Type EMPTY>
<!ATTLIST Type ticket-id CDATA #REQUIRED>

<!ELEMENT PerUse (Currency?)>
<!ATTLIST PerUse value CDATA #REQUIRED>

<!ELEMENT Currency EMPTY>
<!ATTLIST Currency iso-currency-code CDATA #REQUIRED>

<!ELEMENT MeteredFee (Rate, Per, By?)>

<!ELEMENT Rate (Currency?)>
<!ATTLIST Rate value CDATA #REQUIRED>

<!ELEMENT Per EMPTY>
<!ATTLIST Per %interval;>

<!ELEMENT By EMPTY>
<!ATTLIST By %interval;>

<!ELEMENT BestPriceUnder (Currency?)>
<!ATTLIST BestPriceUnder value CDATA #REQUIRED>

<!ELEMENT CallForPrice EMPTY>
<!ATTLIST CallForPrice dealer-id CDATA #REQUIRED>

<!ELEMENT Markup EMPTY>
<!ATTLIST Markup percentage CDATA #REQUIRED>

<!ELEMENT Min (Rate, Per)>
<!ELEMENT Max (Rate, Per)>

<!ELEMENT Account ((AccountTo, House?) | (AccountFrom, House?))>

<!ELEMENT AccountTo EMPTY>
<!ATTLIST AccountTo account-id CDATA #REQUIRED>

<!ELEMENT AccountFrom EMPTY>
<!ATTLIST AccountFrom account-id CDATA #REQUIRED>

<!ELEMENT House EMPTY>
<!ATTLIST House clearing-house-id CDATA #REQUIRED>

<!-- ********* Fee Ended ************* -->

<!-- ********* Access Started ************* -->
<!ELEMENT Access (Security*, User?, Source?, Destination?)>
<!ELEMENT Security EMPTY>
<!ATTLIST Security name CDATA #REQUIRED
                   value CDATA #REQUIRED>

<!ELEMENT User (Any | Certificate+)>
<!ELEMENT Any (Certificate+)>

<!ELEMENT Source (Any | Certificate+)>
<!ELEMENT Destination (Any | Certificate+)>

<!ELEMENT Certificate (Authority, PropertyPair*)>

<!ELEMENT PropertyPair EMPTY>
<!ATTLIST PropertyPair name CDATA #REQUIRED
                       value CDATA #REQUIRED>

<!-- ********* Access Ended ************* -->

<!-- ********* Watermark Started ************* -->
<!ELEMENT Watermark ((Watermark-Str |Watermark-Tokens | Watermark-Object)*)>

<!ELEMENT Watermark-Str EMPTY>
<!ATTLIST Watermark-Str string CDATA #REQUIRED>

<!ELEMENT Watermark-Tokens EMPTY>
<!ATTLIST Watermark-Tokens all-rights (true|false) "false"
                           render-rights (true|false) "false"
                          user-name (true|false) "false"
                          user-id (true|false) "false"
                          user-location (true|false) "false"
                          institution-name (true|false) "false"
                          institution-id (true|false) "false"
                          institution-location (true|false) "false"
                          render-name (true|false) "false"
                          render-id (true|false) "false"
                          render-location (true|false) "false"
                          render-time (true|false) "false"
                          copy-number  (true|false) "false"
                          >

<!ELEMENT Watermark-Object (WorkId)>

<!-- ********* Watermark Ended ************* -->

<!-- ********* Work Ended ************* -->