<front>

<front> (front matter) contains any prefatory matter (headers, abstracts, title page, prefaces, dedications, etc.) found at the start of a document, before the main body. [4.6. Title Pages 4. Default Text Structure]
Module textstructure
Attributes Attributes att.global (xml:id, n, xml:lang) (lim.att.global.fragmentable (part)) (att.global.rendition (rendition)) (att.global.source (source))
Contained by
textstructure: text
transcr: facsimile
May contain
core: divGen ellipsis gap head lb listBibl milestone note noteGrp p pb
figures: figure
lim: NB noteMarker rule
linking: ab linkGrp
textstructure: byline closer dateline div docAuthor docDate docEdition docImprint docTitle epigraph postscript salute signed titlePage titlePart trailer
transcr: fw
Note
Because cultural conventions differ as to which elements are grouped as front matter and which as back matter, the content models for the front and back elements are identical.
Examples

<front>
   <epigraph>
      <quote>Nam Sibyllam quidem Cumis ego ipse oculis meis vidi in ampulla
      pendere, et cum illi pueri dicerent: <q xml:lang="grc">Σίβυλλα τί
      θέλεις</q>; respondebat illa: <q xml:lang="grc">ὰποθανεῖν θέλω.</q>
      </quote>
   </epigraph>
   <div type="dedication">
      <p>For Ezra Pound <q xml:lang="it">il miglior fabbro.</q>
      </p>
   </div>
</front>

<front>
   <div type="dedication">
      <p>To our three selves</p>
   </div>
   <div type="preface">
      <head>Author's Note</head>
      <p>All the characters in this book are purely imaginary, and if the
      author has used names that may suggest a reference to living persons
      she has done so inadvertently. ...</p>
   </div>
</front>

<front>
   <div type="abstract">
      <div>
         <head> BACKGROUND:</head>
         <p>Food insecurity can put children at greater risk of obesity because
        of altered food choices and nonuniform consumption patterns.</p>
      </div>
      <div>
         <head> OBJECTIVE:</head>
         <p>We examined the association between obesity and both child-level
        food insecurity and personal food insecurity in US children.</p>
      </div>
      <div>
         <head> DESIGN:</head>
         <p>Data from 9,701 participants in the National Health and Nutrition
        Examination Survey, 2001-2010, aged 2 to 11 years were analyzed.
        Child-level food insecurity was assessed with the US Department of
        Agriculture's Food Security Survey Module based on eight
        child-specific questions. Personal food insecurity was assessed with
        five additional questions. Obesity was defined, using physical
        measurements, as body mass index (calculated as kg/m2) greater than
        or equal to the age- and sex-specific 95th percentile of the Centers
        for Disease Control and Prevention growth charts. Logistic
        regressions adjusted for sex, race/ethnic group, poverty level, and
        survey year were conducted to describe associations between obesity
        and food insecurity.</p>
      </div>
      <div>
         <head> RESULTS:</head>
         <p>Obesity was significantly associated with personal food insecurity
        for children aged 6 to 11 years (odds ratio=1.81; 95% CI 1.33 to
        2.48), but not in children aged 2 to 5 years (odds ratio=0.88; 95%
        CI 0.51 to 1.51). Child-level food insecurity was not associated
        with obesity among 2- to 5-year-olds or 6- to 11-year-olds.</p>
      </div>
      <div>
         <head> CONCLUSIONS:</head>
         <p>Personal food insecurity is associated with an increased risk of
        obesity only in children aged 6 to 11 years. Personal
        food-insecurity measures may give different results than aggregate
        food-insecurity measures in children.</p>
      </div>
   </div>
</front>
Source Github

<elementSpec module="textstructure" ident="front">
   <gloss>front matter</gloss>
   <desc>contains any prefatory matter
  (headers, abstracts, title page, prefaces, dedications, etc.) found at the
 start of a document, before the main body.</desc>
   <classes>
      <memberOf key="att.global"/>
   </classes>
   <content>
      <sequence>
         <alternate minOccurs="0" maxOccurs="unbounded">
            <classRef key="model.frontPart"/>
            <classRef key="model.pLike"/>
            <classRef key="model.pLike.front"/>
            <classRef key="model.global"/>
         </alternate>
         <sequence minOccurs="0">
            <alternate>
               <sequence>
                  <classRef key="model.div1Like"/>
                  <alternate minOccurs="0" maxOccurs="unbounded">
                     <classRef key="model.div1Like"/>
                     <classRef key="model.frontPart"/>
                     <classRef key="model.global"/>
                  </alternate>
               </sequence>
               <sequence>
                  <classRef key="model.divLike"/>
                  <alternate minOccurs="0" maxOccurs="unbounded">
                     <classRef key="model.divLike"/>
                     <classRef key="model.frontPart"/>
                     <classRef key="model.global"/>
                  </alternate>
               </sequence>
            </alternate>
            <sequence minOccurs="0">
               <classRef key="model.divBottom"/>
               <alternate minOccurs="0" maxOccurs="unbounded">
                  <classRef key="model.divBottom"/>
                  <classRef key="model.global"/>
               </alternate>
            </sequence>
         </sequence>
      </sequence>
   </content>
</elementSpec>