<!-- ============================================================= -->
<!--  MODULE:    BITS Question and Answer Module                   -->
<!--  DATE:      April 2018                                        --> 
<!--                                                               -->
<!-- ============================================================= -->

<!-- ============================================================= -->
<!--                    PUBLIC DOCUMENT TYPE DEFINITION            -->
<!--                        TYPICAL INVOCATION                     -->
<!--
"-//NLM//DTD BITS Question and Answer Module v2.1 20180401//EN"
Delivered as file "BITS-question-answer2.ent"                      -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!-- SYSTEM:     Book Interchange Tag Suite                        -->
<!--                                                               -->
<!-- PURPOSE:    Defines a model for questions, sets of questions, -->
<!--             and answers. This is a very basic model, expected -->
<!--             to be extended. NOTE: This is NOT a model for a   -->
<!--             quiz, test, or exam; such a containing model      -->
<!--             could be built using sections and the questions   -->
<!--             answers defined in this module.                   -->
<!--                                                               -->
<!-- TAG SET SPONSOR                                               -->
<!--             National Center for Biotechnology                 -->
<!--                Information (NCBI)                             -->
<!--             National Library of Medicine (NLM)                -->
<!--                                                               -->
<!-- CREATED FOR:                                                  -->
<!--             This DTD was created as a superset customization  -->
<!--             of the ANSI/NISO JATS Z39.96-2012 Version 1.0     -->
<!--             Journal Article Tag Set.                          -->
<!--                                                               -->
<!--             Digital archives and publishers may use the       -->
<!--             DTD as is for markup of books or book-like        -->
<!--             material for archiving and transferring           -->
<!--             such material between archives or they may create -->
<!--             a custom XML DTD from the BITS Suite for          -->
<!--             these purposes.                                   -->
<!--                                                               -->
<!--             This DTD is in the public domain. An organization -->
<!--             that wishes to create its own DTD from the suite  -->
<!--             may do so without permission from NLM.            -->
<!--                                                               -->
<!--             The suite has been set up to be extended using a  -->
<!--             new DTD file and new DTD-specific customization   -->
<!--             modules to redefine the many Parameter Entities.  -->
<!--             Do not modify the suite directly or redistribute  -->
<!--             modified versions of the suite.                   -->
<!--                                                               -->
<!--             In the interest of maintaining consistency and    -->
<!--             clarity for potential users, NLM requests:        -->
<!--                                                               -->
<!--             1. If you create a DTD from the BITS DTD Suite    -->
<!--                and intend to stay compatible with the suite,  -->
<!--                then please include the following statement    -->
<!--                as a comment in all of your DTD modules:       -->
<!--                   "Created from, and fully compatible with,   -->
<!--                    the Book Interchange Tag Suite (BITS).     -->
<!--                                                               -->
<!--             2. If you alter one or more modules of the suite, -->
<!--                then please rename your version and all its    -->
<!--                modules to avoid any confusion with the        -->
<!--                original suite. Also, please include the       -->
<!--                following statement as a comment in all your   -->
<!--                DTD modules:                                   -->
<!--                   "Based in part on, but not fully compatible -->
<!--                    with, the Book Interchange Tag Suite       -->
<!--                    (BITS)."                                   -->
<!--                                                               -->
<!-- ORIGINAL CREATION DATE:                                       -->
<!--             May 2013                                          -->
<!--                                                               -->
<!-- CREATED BY: Mulberry Technologies, Inc. for the National      -->
<!--             National Center for Biotechnology Information     -->
<!--             (NCBI), a center of the US National Library of    -->
<!--             Medicine (NLM).                                   -->
<!--                                                               -->
<!--             The BITS Book Interchange DTD is built from the   -->
<!--             Journal Archiving and Interchange DTD of the      -->
<!--             ANSI/NISO Journal Article Tag Suite (JATS)        -->
<!--             Version 1.1d1 (Z39.96-2015).                      -->
<!--                                                               -->
<!--             Suggestions for refinements and enhancements to   -->
<!--             this DTD should be sent in email to:              -->
<!--                 bits@ncbi.nlm.nih.gov                         -->
<!-- ============================================================= -->


<!-- ============================================================= -->
<!--                    DTD VERSION/CHANGE HISTORY                 -->
<!-- ============================================================= -->
<!--
Version  Reason/Occasion                   (who) vx.x (yyyy-mm-dd)
    =============================================================
     BITS Version 2.1                (DAL/BTU) v2.1    (2018-04-01)
     JATS Version 1.2d2              (DAL/BTU) v1.2d2  (2018-04-01)

     JATS is a continuing maintenance NISO Standard, which
     requires voting by the ANSI and NISO memberships to be changed. 
     BITS is under continuous maintenance, and is modified at the
     discretion of the working group.

 13. BITS "2.0" and "v2.0 20151225" became
     BITS "2.1" and "v2.1 20180401". 
   
     JATS "1.2d1" and "v1.2d1 20171231" became
     JATS "1.2d2" and "v1.2d2 20180401". 

     No module names were changed.      =============================================================
     BITS Version 2.0                (DAL/BTU) v2.0  (2015-12-25)
     JATS Version 1.1                (DAL/BTU) v1.1  (2015-12-15)

     JATS is a continuing maintenance NISO Standard, which
     requires voting by the ANSI and NISO memberships to be changed. 
     JATS 1.1 was approved in late 2015, and BITS modified to use
     the most recent version. No other changes to BITS were made.
 
 12. BITS remained version "2.0" but became "v2.0 20151225"
     JATS became version "1.1" and "v1.1 20151215"

   =============================================================
     BITS Version 2.0                (DAL/BTU) v2.0    (2015-03-15)
     JATS Version 1.1                (DAL/BTU) v1.1    (2015-03-01)

     BITS was modified, based on user feedback collected in 2014 
     and January/February 2015, according to the decisions
     made by the BITS Working Group. This DTD represents current 
     BITS and an interim version of the non-normative JATS DTD 
     Suite (version 1.1), as an indication to JATS users of 
     the decisions that have been made by the JATS Standing
     Committee. 

     NISO JATS is a continuing maintenance NISO Standard, which
     requires voting by the NISO membership to be changed. This
     Committee Draft 1.1 will be sent to the NISO voting
     membership, to become (if approved) NISO JATS 1.1.

 11. TITLE/SUBTITLE/ALT-TIT/E ETC. - Some of the question/answer
     components could take subtitles and alt-titles as well as titles,
     but all could not. Regularized them to include all title
     tyoes if a title was possible.

 10. EXPLANATION - was given a new section-level model similar
     to that for <answer>.

  9. ANSWER-SPECIFIC PARAGRAPH-LEVEL OBJECTS
     Created a new PE (answer-para-level) to prohibit 
     <explanation> at the paragraph level inside
     <answer>, because that created DTD determinism problems.
     Rewrote <answer> model to use this PE.

  8. QUESTION MODEL - changed the model for <question> to:
      - call all the components of sec-opt-title-model
        rather than calling the grouping PE
      - Add new element <option>, which is used for multiple 
        choice questions (instead of <answer>) 

  7. ANSWER/QUESTION ATTRIBUTES
      - Removed @correct (yes | no) from <answer> and from
        <answer-set>, because, by definition, an <answer> 
        is correct. The <option> element may now be marked 
        with a @correct attribute ('yes' or 'no').
      -Removed @answer-type from <answer>, since this is 
       really about the question, not the answer.
     - Added new attribute @question-response-type to
       <question>, which takes the old values for @answer-type
       (multiple choice, short answer, essay, etc.) 

  6. XML:LANG ATTRIBUTE - Added @xml:lang to the attributes lists
     of <question-wrap> and <question-wrap-group>. 

  5. EXPLANATION - Added @rid to <explanation> since these can
     now float in the text as answers can. 

  4. QUESTION-PREAMBLE - Added new element to hold setup/
     preamble information, when the setup is shared by several 
     questions, for example, a diagram is shown and the questions
     are similar to "What is angle a?". This preamble is part of
     a <question-wrap-group> that contains the preamble/setup 
     (<question-preamble>) and several questions
     (<question-wrap>).

  3. QUESTION-WRAP-GROUP - Added new element <question-wrap-group>
     to hold a question setup/preamble (<question-preamble>)
     and two or more <question-wrap>s based on that preamble.

  2. BITS became version "2.0" and   "v2.0 20150630"
     JATS became version "1.1" and "v1.1 20150301"

     =============================================================
     BITS Version 1.1                (DAL/BTU) v1.1    (2014-09-30)
     JATS Version 1.1d2              (DAL/BTU) v1.1d2  (2014-09-30)

     NISO JATS is a continuing maintenance NISO Standard, which
     requires voting by the NISO membership to be changed. This
     Committee Draft 1.1d2 will be sent to the NISO voting
     membership, to become (if approved) NISO JATS 1.1.

     This catalog represents an interim version of the
     non-normative JATS DTD Suite, as an indication to JATS users
     the decisions that have been made by the JATS Standing
     Committee.

  1. BITS became version "1.1" and   "v1.1 20140930//EN"
     JATS became version "1.1d2" and "v1.1d2 20140930//EN"

     =============================================================
                                                                   -->


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR ATTRIBUTE VALUES    -->
<!-- ============================================================= -->


<!--                    TYPES OF ANSWERS                           -->
<!--                    Used to name the type of question or
                        question set.                              -->
<!ENTITY % answer-types "essay | fill-in-the-blank | multi-select |
                         multiple-choice | short-answer |
                         true-false"                                 >


<!-- ============================================================= -->
<!--                    PARAMETER ENTITIES FOR ATTRIBUTE LISTS     -->
<!-- ============================================================= -->


<!--                    QUESTION ATTRIBUTES                        -->
<!--                    Attributes for the <question> element      -->
<!ENTITY % question-atts
           "%jats-common-atts;
             question-response-type
                        (%answer-types;)                  #IMPLIED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    QUESTION PREAMBLE ATTRIBUTES               -->
<!--                    Attributes for the <question-preamble> 
                                                           element -->
<!ENTITY % question-preamble-atts
           "%jats-common-atts;
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    QUESTION WRAP ATTRIBUTES                   -->
<!--                    Attributes for the <question-wrap> element -->
<!ENTITY % question-wrap-atts
           "%jats-common-atts;
             audience   CDATA                             #IMPLIED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    QUESTION WRAP GROUP ATTRIBUTES             -->
<!--                    Attributes for the <question-wrap-group> 
                        element                                    -->
<!ENTITY % question-wrap-group-atts
           "%jats-common-atts;
             audience   CDATA                             #IMPLIED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    ANSWER ATTRIBUTES                          -->
<!--                    Attributes for the <answer> element        -->
<!ENTITY % answer-atts
           "%jats-common-atts;
             pointer-to-question
                        IDREFS                            #REQUIRED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    ANSWER SET ATTRIBUTES                      -->
<!--                    Attributes for the <answer-set> element    -->
<!ENTITY % answer-set-atts
           "%jats-common-atts;
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    EXPLANATION ATTRIBUTES                     -->
<!--                    Attributes for the <explanation> element   -->
<!ENTITY % explanation-atts
           "%jats-common-atts;
             pointer-to-explained
                        IDREFS                            #REQUIRED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!--                    OPTION ATTRIBUTES                          -->
<!--                    Attributes for the <option> element        -->
<!ENTITY % option-atts  
           "%jats-common-atts;
             correct    (yes | no)                        #IMPLIED
             content-type
                        CDATA                             #IMPLIED
             specific-use
                        CDATA                             #IMPLIED
             xml:lang   NMTOKEN                           #IMPLIED"  >


<!-- ============================================================= -->
<!--                    QUESTION ELEMENTS                          -->
<!-- ============================================================= -->


<!--                    QUESTION MODEL                             -->
<!--                    Content model for the <question> element.  -->
<!ENTITY % question-model
                        "((%id.class;)*, sec-meta?,
                         label?, title?, subtitle*, alt-title*,
                         ( (%sec-level;)+ |
                           ( (%para-level;)+, (%sec-level;)* ) ),
                         (%option.class;)*,
                         (%sec-back-matter-mix;)* )"                 > 
 

<!--                    QUESTION                                   -->
<!--                    A question (request for an answer) used in
                        the text or as part of a quiz, exam, etc.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=question
                                                                   -->
<!ELEMENT  question     %question-model;                             >
<!ATTLIST  question
            %question-atts;                                          >



<!--                    QUESTION WRAP MODEL                        -->
<!--                    Content model for the <question-wrap>
                        element.                                   -->
<!ENTITY % question-wrap-model
                        "((%id.class;)*, question,
                          (answer | answer-set)?, explanation*)"     >


<!--                    QUESTION WRAP                              -->
<!--                    Used to model a Question/Answer scheme. These
                        questions may be used, for example, for the
                        Continuing Medical Education articles in a
                        book of articles. The model allows for
                        simple questions followed by their
                        corresponding answers or for a multiple
                        choice setup, where questions are followed
                        by multiple alternative answers (<option>s), 
                        along with the correct answer and an 
                        explanation.
                        Note: This is not the model for a full
                        quiz, test, exam, etc., but such a model
                        could be built using these components for
                        the question/answers.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=question-wrap
                                                                   -->
<!ELEMENT  question-wrap
                        %question-wrap-model;                        >
<!ATTLIST  question-wrap
            %question-wrap-atts;                                     >


<!--                    QUESTION WRAP GROUP MODEL                  -->
<!--                    Content model for the <question-wrap-group>
                        element.                                   -->
<!ENTITY % question-wrap-group-model
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          question-preamble?, 
                          (%question-wrap.class;)+ )"                >


<!--                    QUESTION WRAP GROUP                       -->
<!--                    A container element used to hold a group of
                        <question-wrap> elements, for example, when
                        all the questions share a common preamble 
                        (setup).
                        Note: This is not the model for a full
                        quiz, test, exam, etc., but such a model
                        could be built using these components for
                        the question/answers.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=question-wrap-group
                                                                   -->
<!ELEMENT  question-wrap-group
                        %question-wrap-group-model;                  >
<!ATTLIST  question-wrap-group
            %question-wrap-group-atts;                               >


<!--                    QUESTION PREAMBLE MODEL                    -->
<!--                    Content model for the <question-preamble>
                        element.                                   -->
<!ENTITY % question-preamble-model
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          (%para-level;)*, (%sec.class;)*  )"        >


<!--                    QUESTION PREAMBLE                          -->
<!--                    A container element used setup/
                        preamble information when the setup is shared 
                        by several questions, for example, a diagram 
                        is shown and the questions are similar to 
                        "What is angle a?".
                        Remarks: The preamble information is part of
                        a <question-wrap-group> that contains the 
                        preamble/setup (<question-preamble>) and 
                        several questions (tagged as <question-wrap>s).
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=question-preamble
                                                                   -->
<!ELEMENT  question-preamble
                        %question-preamble-model;                    >
<!ATTLIST  question-preamble
            %question-preamble-atts;                                 >



<!-- ============================================================= -->
<!--                    ANSWER/EXPLANATION ELEMENTS                -->
<!-- ============================================================= -->


<!--                    ANSWER MODEL                               -->
<!--                    Content model for the <answer> element.    -->
<!ENTITY % answer-model
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          ( (%sec-level;)+ |
                            ( (%answer-para-level;)+, 
                              (%sec-level;)* ) ),
                          (%sec-back-matter-mix;)*,
                           explanation*)"                           >
                           

<!--                    ANSWER ELEMENTS                            -->
<!--                    An answer to a question
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=answer
                                                                   -->
<!ELEMENT  answer       %answer-model;                               >
<!ATTLIST  answer
            %answer-atts;                                            >

<!--                    ANSWER SET MODEL                           -->
<!--                    Content model for the <answer-set> element.-->
<!ENTITY % answer-set-model
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          (answer | %just-para.class; |
                           explanation)+)"                           >


<!--                    ANSWER SET                                 -->
<!--                    A series of answers, typically in response
                        to a question.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=answer-set
                                                                   -->
<!ELEMENT  answer-set   %answer-set-model;                           >
<!ATTLIST  answer-set
            %answer-set-atts;                                        >


<!--                    EXPLANATION MODEL                          -->
<!--                    Content model for the <answer-set> element.-->
<!ENTITY % explanation-model
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          ( (%sec-level;)+ |
                            ( (%answer-para-level;)+, 
                              (%sec-level;)* ) ),
                          (%sec-back-matter-mix;)*)"                 >


<!--                    EXPLANATION                                -->
<!--                    A description of a question/answer or of just
                        an answer or answer set. The explanation
                        may describe, for example, why this
                        particular answer is incorrect, or where in
                        the text the material for this question
                        can be found, et al.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=explanation
                                                                   -->
<!ELEMENT  explanation  %explanation-model;                          >
<!ATTLIST  explanation
            %explanation-atts;                                       >


<!--                    OPTION MODEL                               -->
<!--                    Content model for the <option> element.    -->
<!ENTITY % option-model 
                        "((%id.class;)*,
                          label?, title?, subtitle*, alt-title*,
                          ( (%sec-level;)+ |
                            ( (%answer-para-level;)+, 
                              (%sec-level;)* ) ),
                          (%sec-back-matter-mix;)*,
                           explanation*)"                           >


<!--                    OPTION ELEMENTS                            -->
<!--                    One of the possible answer-choices for a 
                        multiple-choice question. An attribute can be
                        used to identify options which are correct.
                        Details at:
                        http://jats.nlm.nih.gov/extensions/bits/2.1/index.html?elem=option
                                                                   -->
<!ELEMENT  option       %option-model;                               >
<!ATTLIST  option
            %option-atts;                                            >


<!-- ================== End BITS Question and Answer Module ====== -->

