XML Sample DTD13 (Version 1.3)
XML見本DTD13(版数1.3)
Copyright (C) 1998, 1999 Nihon Unisys,Ltd., All rights reserved
This XML sample DTD13 has been derived by Nihon Unisys,Ltd.
from NCALS-Technical Manual DTD Version 2.1 and some HTML syntax has
been added so that a document can be imaged by commercial browser,
such as MS-IE4.0 or more.
<!-- (C) Nihon Unisys,Ltd. 1998, 1999
Permission to copy in any form is granted for use with conforming
XML system and applications as defined in this
Document Type Definition(DTD), provided this notice in all copies.
-->
<!-- The definition written in natural language shall be
referenced before reading this formal definition.-->
<!-- The following set of declarations may be refered to
by using a public entity as follows:
<!-- NOTE:
- The aims of the DTD are to establish a class of DTD
and to make create some DTDs for various applications
under the generic DTD in Japan.
- The outline of this DTD are as follows:
- Base functions are imported from USA/MIL-STD-38784
Amendment 3,
- Japanese character handling using JIS(G1)kanji code,
- Add the notation for ISO 9000 series
- In order to parse the following DTD subset alone,
append the following statement to begining if the file:
<!DOCTYPE doc [
and the associated "]>" til the end of file. -->
- The source code of the DTD in clear text
<!-- ENTITY DECLARATIONS -->
<!-- Parameter Entity Declaration for Common Usage -->
<!-- The following five parameter entities were added by Miike on Wakatori's advice -->
<!ENTITY % yesorno "CDATA">
<!ENTITY % useratt "useratt1 CDATA #IMPLIED
useratt2 CDATA #IMPLIED
useratt3 CDATA #IMPLIED
useratt4 CDATA #IMPLIED
useratt5 CDATA #IMPLIED" >
<!ENTITY % content "applicrefid IDREFS #IMPLIED
assocfig IDREFS #IMPLIED
assoctab IDREFS #IMPLIED">
<!ENTITY % bodyatt "id ID #IMPLIED
inschlvl NMTOKENS #IMPLIED
delchlvl NMTOKENS #IMPLIED
revchg %yesorno; '0'
%content;
%useratt; ">
<!ENTITY % RE "
" >
<!ENTITY % URL "#PCDATA" >
<!ENTITY % shortitle " " >
<!ENTITY % captions "(caption %shortitle;)" >
<!ENTITY % list "(ol | ul | dl)" >
<!ENTITY % safetylvl "(warning*,caution*,notice*,danger*)" >
<!ENTITY % spcpara "(warning?,caution?,notice?,danger?)" >
<!ENTITY % text "((#PCDATA | ftnref | xref | indxflag |
emphasis | img | subscrpt | supscrpt | extref |
mathtxt | a | wordref | hr | br)*)" >
<!ENTITY % textcont "(para*,note*,(step1+)?) " -- added by NCALS-DTD version 1.4 -- >
<!ENTITY % userelms "(userelm1?,userelm2?,userelm3?,userelm4?,
userelm5?,userelm6?,userelm7?,userelm8?,userelm9?,userelm10?)" >
<!-- Parameter Entity Declaration in Alphabert Sequence -->
<!ENTITY % append "((((%captions;)?,para) | figure |
table | warning | caution | notice | danger | note | img | step1)+)" >
<!ENTITY % bodyele "(chapter+, ddchapter?)" >
<!ENTITY % change "(#PCDATA | ftnref | xref | indxflag |
img | subscrpt | supscrpt | extref | mathtxt | a)+" >
<!ENTITY % chap "(%captions;,(%textcont;)*,(section* | para0*)?)" >
<!ENTITY % chgsht "(chgnum, date, caption, para?, chglist)" >
<!ENTITY % ddchap "(ddintro, ddsheet+)" >
<!ENTITY % fig "(%captions;, (img | macrograph | figcap)+)" >
<!ENTITY % fpi "(para0, (para0 | %list; | abbrsect |
%spcpara;)*, lrp?)" >
<!ENTITY % frnt "(idinfo, warnpage?, chginssht?, lep,
verstat?, chgrec?,contents, illuslist?, tablelist?,
(foreword | preface | intro))" >
<!ENTITY % idinf "(volnum?,docpartn?,revnum?,distlist*,caption,
stitle?,seal?,supersed?,discl,expcont?,pubdate,
(chgnum,chgdate,approver*,revisor*,docref?,revcmnts?)*,
preparer*,copyright,owner*,usercode*,%userelms;?)" >
<!ENTITY % imgatt "SRC %URL; #IMPLIED"> <!--changed boardno to SRC for XML -->
<!ENTITY % lrp "(caption)+" >
<!ENTITY % glossry "(dl+)" >
<!ENTITY % mctext "((ftnref | xref | indxflag | emphasis |
img | subscrpt | supscrpt | extref | mathtxt | a | wordref | hr | br)+)" >
<!ENTITY % mrelems "mrpara | mrlist | img" >
<!ENTITY % mrinfo "(pubno+,(revnum|(chgnum, chgdate)|
pubdate))" >
<!ENTITY % mrtext "#PCDATA" -- symbol is deleted for XML -->
<!ENTITY % namelist "(person*,organ?)">
<!ENTITY % nparcon "(%safetylvl;, %captions;,%textcont;)" >
<!ENTITY % nparcon1 "(%safetylvl;,(%captions;)?,%textcont;)" >
<!ENTITY % num "(#PCDATA)" >
<!ENTITY % paracon "((ttext | %list; | table | | mathcon)+)" >
<!-- The following parameter entity was recovered by Miike -->
<!ENTITY % parazero "(%captions;, %safetylvl;,(%textcont;)*, subpara1*)* >
<!ENTITY % rr "(appendix*,glossary?,index?)" >
<!ENTITY % sect "(%captions;,((%textcont;) | para0)*)" >
<!ENTITY % secur "security (u | c | s) 'u' " >
<!ENTITY % step1con "(%safetylvl;,para*,note*),(step2+)?" >
<!ENTITY % step2con "(%safetylvl;,para*,note*),(step3+)?" >
<!ENTITY % step3con "(%safetylvl;, para*, note*),(step4+)?" >
<!ENTITY % step4con "(%safetylvl;, para*, note*),(step5+)?" >
<!ENTITY % step5con "(%safetylvl;,para*,note*),(step6+)?" >
<!ENTITY % step6con "(%safetylvl;,para*,note*),(step7+)?" >
<!ENTITY % step7con "(%safetylvl;,para*,note*)" >
<!ENTITY % tabl "(%captions;, tgroup+)" >
<!ENTITY % td "(ttext | %list; | mathcon)+" >
<!ENTITY % termele "(%mctext;, ftnote*)" >
<!-- Common Attributes -->
<!ENTITY % docatt "docid ID #REQUIRED
docstat ( revision | change | prelim | draft | formal ) 'prelim'" >
<!ENTITY % stepatt "id ID #IMPLIED
inschlvl NMTOKEN #IMPLIED
delchlvl NMTOKEN #IMPLIED
revchg NMTOKEN #IMPLIED
applicrefid IDREFS #IMPLIED
assocfig IDREFS #IMPLIED
assoctab IDREFS #IMPLIED
useratt1 NMTOKEN #IMPLIED
useratt2 NMTOKEN #IMPLIED
useratt3 NMTOKEN #IMPLIED
useratt4 NMTOKEN #IMPLIED
useratt5 NMTOKEN #IMPLIED" >
<!ENTITY % tdatt "colname NMTOKEN #IMPLIED
spanname NMTOKEN #IMPLIED
morerows NMTOKEN #IMPLIED
valign ( top | middle | bottom ) 'bottom'
align ( left | right | center | justify | char ) 'center'
charoff NMTOKEN #IMPLIED
char CDATA #IMPLIED " >
<!-- NOTATION DECLARATIONS (v1r00)-->
<!NOTATION cgm PUBLIC "-//NCALS//NOTATION Computer
Graphics Metafile//EN" >
<!NOTATION t6 PUBLIC "-//NCALS//NOTATION I
Raster Graphics//EN" >
<!NOTATION eqn PUBLIC "-//NCALS//NOTATION A Langage
for Typesetting Mathematics//EN" >
<!NOTATION TeX PUBLIC "-//NCALS//NOTATION TeX//EN">
<!NOTATION JPEG PUBLIC "-//NCALS//NOTATION
Photographic Codings(jpeg)//EN">
<!NOTATION MPEG PUBLIC "-//NCALS//NOTATION
Coding of Moving Pictures and Associated Audio for
Digital Storage Media at up to about 1.5 Mbit/s//EN">
<!NOTATION IGES PUBLIC "-//NCALS//NOTATION
Initial Graphics Exchange Specification(IGES)//EN">
<!NOTATION audio PUBLIC "-//NCALS//NOTATION
Audio Codings//EN">
<!NOTATION CDIF PUBLIC "-//NCALS//NOTATION
CASE Data Interchange Format//EN">
<!NOTATION GIF PUBLIC "-//W3C//NOTATION
Graphic Interchange Format//EN">
<!-- ELEMENT and ATTRIBUTE LIST DECLARATIONS -->
<!ELEMENT a (URL)>
<!ATTLIST a NAME NMTOKEN #IMPLIED
HREF CDATA #IMPLIED
%secur; >
<!ELEMENT appendix (%append;), (ftnote) >
<!ATTLIST appendix tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT approver (person*,position?,
organ?) >
<!ATTLIST approver %secur; >
<!ELEMENT body (%bodyele;),(ftnote | change) >
<!ATTLIST body %secur; >
<!ELEMENT br EMPTY >
<!ATTLIST br %RE; >
<!-- Entity caption was revised by Miike May 1999 -->
<!ELEMENT caption (#PCDATA | a | number)* >
<!ATTLIST caption %secur; >
<!ELEMENT caution (img?, (para+, (%list;)*)+) >
<!ATTLIST caution type NMTOKEN #IMPLIED
xrefid IDREF #IMPLIED
%secur; >
<!ELEMENT change (%change;) >
<!ATTLIST change level NMTOKEN #IMPLIED
change (add | delete) "add"
mark NMTOKEN #IMPLIED
%secur; >
<!ELEMENT chghistdate (#PCDATA) >
<!ELEMENT chapter (a?, %chap;) >
<!ATTLIST chapter tocentry NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT chgdate (#PCDATA) >
<!ELEMENT chginssht (%chgsht;) >
<!ATTLIST chginssht verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT chglist ((remove, insert)+) >
<!ELEMENT chgnum (#PCDATA) >
<!ELEMENT chgrec (table) >
<!ELEMENT colspec EMPTY >
<!ATTLIST colspec colnum NMTOKEN #IMPLIED
colname NMTOKEN #IMPLIED
align (left | right | center |
justify | char) "center"
charoff NMTOKEN #IMPLIED
char CDATA #IMPLIED
colwidth CDATA #IMPLIED >
<!ELEMENT contents EMPTY >
<!ATTLIST contents verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT copyright (#PCDATA) >
<!ATTLIST copyright %secur; >
<!ELEMENT date (%text;) >
<!ELEMENT danger (img?, (para+, (%list;)*)+) >
<!ATTLIST danger type NMTOKEN #IMPLIED
xrefid IDREF #IMPLIED
%secur; >
<!ELEMENT dd (%text;) >
<!ATTLIST dd %secur; >
<!ELEMENT ddchapter (%ddchap;) >
<!ATTLIST ddchapter tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT dddesc (para0+) >
<!ATTLIST dddesc %secur; >
<!ELEMENT ddindex (para0+, ddlist) >
<!ATTLIST ddindex %secur; >
<!ELEMENT ddintro (caption, dddesc, ddindex) >
<!ATTLIST ddintro %secur; >
<!ELEMENT ddlist ((partno, pos)+) >
<!ATTLIST ddlist %secur; >
<!ELEMENT ddsheet (caption, para+)* >
<!ATTLIST ddsheet %secur; >
<!ELEMENT dl (caption?, (dt, dd)+) >
<!ATTLIST dl %secur; >
<!ELEMENT discl (#PCDATA) >
<!ELEMENT distlist (%namelist;) >
<!ATTLIST distlist %secur; >
<!ELEMENT doc ((mrinfo,modreq*) |
(volume+) |
(front,body,rear?)) >
<!ATTLIST doc %docatt;
%secur; >
<!ELEMENT docpart ((front,body,rear?))) >
<!ATTLIST docpart tocentry NMTOKEN #IMPLIED
&bodyatt;
&secur; >
<!ELEMENT docpartn (#PCDATA) >
<!ELEMENT docref (#PCDATA)>
<!ELEMENT emphasis (%change;) >
<!ATTLIST emphasis type NAMES #REQUIRED >
<!ELEMENT expcont (#PCDATA) >
<!ELEMENT extref EMPTY >
<!ATTLIST extref docrefid IDREFS #REQUIRED
%secur; >
<!ELEMENT figcap (%text;) >
<!ATTLIST figcap %secur; >
<!ELEMENT figure (%fig;) >
<!ATTLIST figure tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
orient (port | land) "port"
%bodyatt;
%secur; >
<!ELEMENT foreword (%fpi;) >
<!ATTLIST foreword tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT front (%frnt;) >
<!ATTLIST front %secur; >
<!ELEMENT ftnote ((ttext | %list;)+) >
<!ATTLIST ftnote id ID #REQUIRED
mark (ctr | sym) "ctr"
%secur; >
<!ELEMENT ftnref EMPTY >
<!ATTLIST ftnref xrefid IDREF #REQUIRED >
<!ELEMENT glossary (%glossry;) >
<!ATTLIST glossary verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT hr EMPTY >
<!ELEMENT idinfo (%idinf;) >
<!ATTLIST idinfo verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT illuslist EMPTY >
<!ATTLIST illuslist verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT img EMPTY >
<!ATTLIST img %imgatt;
%secur; >
<!ELEMENT index EMPTY >
<!ATTLIST index verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT indxflag EMPTY >
<!ATTLIST indxflag ref1 CDATA #IMPLIED
ref2 CDATA #IMPLIED
ref3 CDATA #IMPLIED
ref4 CDATA #IMPLIED
%secur; >
<!ELEMENT insert (#PCDATA) >
<!ATTLIST insert %secur; >
<!ELEMENT intro (%fpi;) >
<!ATTLIST intro tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT li (ttext, (%list;)*, ftnote*) >
<!ATTLIST li id ID #IMPLIED
%secur; >
<!ELEMENT lep (origdate, chghistdate*)+ >
<!ATTLIST lep verified NMTOKEN #IMPLIED >
<!ELEMENT lrp (%lrp;) >
<!ATTLIST lrp %secur; >
<!ELEMENT macrograph (img+) >
<!ATTLIST macrograph reprowid NMTOKEN #IMPLIED
reprodep NMTOKEN #IMPLIED
%secur; >
<!ELEMENT mathcon (A HREF="pcdata.html">#PCDATA) >
<!ATTLIST mathcon %bodyatt;
%secur; >
<!ELEMENT mathtxt (#PCDATA) >
<!ATTLIST mathtxt %bodyatt;
%secur; >
<!--Beginning of modification request declaration set. NCALS-DTD V2R00-->
<!ELEMENT modreq (mrinfo?,mrmod,mrrespns?) >
<!ATTLIST modreq id ID #REQUIRED
xref NMTOKEN #IMPLIED
refpos (prexref | postxref | xref) "xref"
by CDATA #REQUIRED
date CDATA #REQUIRED
organiz NMTOKEN #IMPLIED
orgcat NMTOKEN #IMPLIED
cmntrcat NMTOKEN #IMPLIED
priority (1|2|3|4) #IMPLIED
category NMTOKEN #IMPLIED
topic CDATA #IMPLIED >
<!ELEMENT mrinfo (%mrinfo;) >
<!ELEMENT mrmod (mrreason?,(mrgenmod | (mrinstr?, mrchgtxt))) >
<!ELEMENT (mrreason | mrinstr | mrgenmod) (%mrelems;)+ >
<!ELEMENT mrchgtxt ANY >
<!ATTLIST mrchgtxt chgloc NMTOKEN #IMPLIED
chglen NMTOKEN #IMPLIED
action (insert | delete | replace) "replace" >
<!ELEMENT mrrespns (%mrelems;)* >
<!ATTLIST mrrespns dispsn NMTOKEN #IMPLIED
status NMTOKEN #IMPLIED >
<!ELEMENT (mrpara | mritem) (%mrtext;) >
<!ELEMENT mrlist (mritem+) >
<!-- End of modification request declaration set,NCALS-DTD V2R00 -->
<!ELEMENT note ((para+, (%list;)*)+) >
<!ATTLIST note type NMTOKEN #IMPLIED
xrefid IDREF #IMPLIED
%secur; >
<!ELEMENT notice (img?, (para+, (%list;)*)+) >
<!ATTLIST notice type NAME #IMPLIED
xrefid IDREF #IMPLIED
%secur; >
<!ELEMENT number (%num;) >
<!ELEMENT ol (caption?, li+) >
%lt;!ATTLIST ol %bodyatt;
%secur; >
<!ELEMENT organ (#PCDATA) >
<!ELEMENT origdate (#PCDATA) >
<!ELEMENT owner (%namelist;) >
<!ELEMENT para %paracon; >
<!ATTLIST para %bodyatt;
%secur; >
<!ELEMENT para0 (%parazero;) >
<!ATTLIST para0 tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT partno (#PCDATA) >
<!ATTLIST partno %secur; >
<!ELEMENT person (#PCDATA) >
<!ATTLIST person %secur; >
<!ELEMENT pos (#PCDATA) >
<!ELEMENT position (#PCDATA) >
<!ATTLIST position %secur; >
<!ELEMENT preface (%fpi;) >
<!ATTLIST preface tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT preparer (%namelist;) >
<!ATTLIST preparer %secur; >
<!ELEMENT pubdate (#PCDATA) >
<!ELEMENT pubno (#PCDATA) >
<!ELEMENT rear (%rr;) >
<!ATTLIST rear %secur; >
<!ELEMENT remove (#PCDATA) >
<!ATTLIST rear %secur; >
<!ELEMENT revcmnts (#PCDATA)>
<!ATTLIST revcmnts %secur; >
<!ELEMENT revisor (person*,position?,organ?)>
<!ATTLIST revisor %secur; >
<!ELEMENT revnum (#PCDATA) >
<!ELEMENT seal (img) >
<!ELEMENT section (%sect;) >
<!ATTLIST section tocentry NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT spanspec EMPTY >
<!ATTLIST spanspec namest NMTOKEN #REQUIRED
nameend NMTOKEN #REQUIRED
spanname NMTOKEN #IMPLIED
align (left | right | center |
justify | char) "center"
charoff NUTOKEN #IMPLIED
char CDATA #IMPLIED >
<!ELEMENT step1 (%step1con;) >
<!ATTLIST step1 %stepatt; >
<!ELEMENT step2 (%step2con;) >
<!ATTLIST step2 %stepatt; >
<!ELEMENT step3 (%step3con;) >
<!ATTLIST step3 %stepatt; >
<!ELEMENT step4 (%step4con;) >
<!ATTLIST step4 %stepatt; >
<!ELEMENT step5 (%step5con;) >
<!ATTLIST step5 %stepatt; >
<!ELEMENT step6 (%step6con;) >
<!ATTLIST step6 %stepatt; >
<!ELEMENT step7 (%step7con;) >
<!ATTLIST step7 %stepatt; >
<!ELEMENT stitle (CDATA) >
<!ATTLIST stitle %secur; >
<!ELEMENT subpara1 (a?, %nparcon;, subpara2*) >
<!ATTLIST subpara1 tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT subpara2 (%nparcon1;, subpara3*) >
<!ATTLIST subpara2 tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT subpara3 (%nparcon1;) >
<!ATTLIST subpara3 tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT subscrpt #PCDATA >
<!ATTLIST subscrpt %secur; >
<!ELEMENT supersed (#PCDATA) >
<!ELEMENT supscrpt #PCDATA >
<!ATTLIST supscrpt %secur; >
<!ELEMENT table (%tabl;) >
<!ATTLIST table tocentry NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
orient (port | land) "port"
align (left | center | right) "center"
%bodyatt;
%secur; >
<!ELEMENT tablelist EMPTY >
<!ATTLIST tablelist verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT tbody (tr+) >
<!ATTLIST tbody valign (top | middle | bottom) "top"
%secur; >
<!ELEMENT td %td; >
<!ATTLIST td %tdatt; %secur; >
<!-- ttext was added by Version 1.3 -->
<!ELEMENT ttext %text;>
<!ELEMENT tfoot (colspec*,tr+) >
<!ATTLIST tfoot valign (top | middle | bottom) "top"
%secur; >
<!ELEMENT tgroup (colspec*,spanspec*,thead?,
tfoot?,tbody) >
<!ATTLIST tgroup cols NMTOKEN #REQUIRED
align (left | right | center |
justify | char) "left"
charoff NMTOKEN #IMPLIED
char CDATA #IMPLIED
%secur; >
<!ELEMENT thead (colspec*,tr+) >
<!ATTLIST thead valign (top | middle | bottom) "bottom"
%secur; >
<!ELEMENT tr ((td)+)
>
<!ATTLIST tr valign (top | bottom |middle) "middle"
bgrcolor CDATA #REQUIRED
%secur; ><!--#ccccff-->
<!ELEMENT ul (caption?, li+) >
<!ATTLIST ul %secur; >
<!ELEMENT usercode (#PCDATA) >
<!ELEMENT userelm1 (#PCDATA) >
<!ELEMENT userelm2 (#PCDATA) >
<!ELEMENT userelm3 (#PCDATA) >
<!ELEMENT userelm4 (#PCDATA) >
<!ELEMENT userelm5 (#PCDATA) >
<!ELEMENT userelm6 (#PCDATA) >
<!ELEMENT userelm7 (#PCDATA) >
<!ELEMENT userelm8 (#PCDATA) >
<!ELEMENT userelm9 (#PCDATA) >
<!ELEMENT userelm10 (#PCDATA) >
<!ELEMENT verstat (warning | caution | notice |
danger)+ >
<!ATTLIST verstat %secur; >
<!ELEMENT volnum (#PCDATA) >
<!ELEMENT volume ((docpart+) | (front,body,rear?)) >
<!ATTLIST volume tocentry NMTOKEN #IMPLIED
%bodyatt;
%secur; >
<!ELEMENT warning (img?, (para+, (%list;)*)+) >
<!ATTLIST warning type NAME #IMPLIED
xrefid IDREF #IMPLIED
%secur; >
<!ELEMENT warnpage ((para | warning)+) >
<!ATTLIST warnpage inschlvl NMTOKENS #IMPLIED
delchlvl NMTOKENS #IMPLIED
revchg NMTOKEN #IMPLIED
verified NMTOKEN #IMPLIED
%secur; >
<!ELEMENT wordref (a | (#PCDATA)) >
<!ATTLIST wordref %secur;
verified NMTOKEN #IMPLIED
category CDATA #IMPLIED
pronunciation CDATA #IMPLIED >
<!ELEMENT xref EMPTY >
<!ATTLIST xref xrefid IDREF #REQUIRED
%secur; >