<alt>

<alt> (替換) 標明一個替換，或是元素或段落之間的一組不同選擇。 16.8 Alternation
組件linking — 16 Linking, Segmentation, and Alignment
屬性att.global (@xml:id, @n, @xml:lang, @rend, @rendition, @xml:base, @xml:space) (att.global.linking (@corresp, @synch, @sameAs, @copyOf, @next, @prev, @exclude, @select)) (att.global.analytic (@ana)) (att.global.facs (@facs)) att.pointing (@target, @evaluate) att.typed (@type, @subtype)
targets標明替換元素或段落的識別符碼。
狀態 非必備的
資料類型 2–∞ 次可出現: 

<rng:ref name="data.pointer"/>
data.pointer
以空白鍵隔開
值 Each value specified must be the same as that specified as value for an xml:id attribute for some other element in the current document.
mode說明在此集合中的替換物件是唯一的或通用的。
狀態 推薦的
合法的值是:
excl
(exclusive) 替換物件是唯一的，例如最多只出現一個替換。
incl
(inclusive) 替換物件不是唯一的，例如出現一個或多個替換。
weights若屬性mode的屬性值是excl，則每個weight皆表明相對應替換的可能性。若屬性mode的屬性值是incl，則每個weight皆表明，在至少一個其他替換存在的前提下，相對應替換的可能性
狀態 非必備的
資料類型 2–∞ 次可出現: 

<rng:ref name="data.probability"/>
data.probability
以空白鍵隔開
值 a whitespace-separated list of probability values in the range from 0 to 1.
屬於
model.global.meta
可包含在於
analysis: cl m phr s span w
core: abbr add addrLine address author bibl biblScope cit corr date del distinct editor email emph expan foreign gloss head headItem headLabel hi imprint item l label lg list measure mentioned name note num orig p pubPlace publisher q quote ref reg resp rs said series sic soCalled sp speaker stage street term time title unclear
corpus: activity channel constitution derivation domain factuality interaction locale preparedness purpose
dictionaries: case colloc def dictScrap entry entryFree etym form gen gram gramGrp hom hyph iType lang lbl mood number orth per pos pron re sense stress subc syll tns usg xr
drama: actor camera caption castGroup castItem castList epilogue performance prologue role roleDesc set sound tech view
figures: cell figure table
header: authority change classCode creation distributor edition extent funder geoDecl handNote language principal scriptNote sponsor typeNote
linking: ab altGrp seg
msdescription: accMat acquisition additions catchwords collation colophon condition custEvent decoNote explicit filiation finalRubric foliation heraldry incipit layout material msItem musicNotation objectType origDate origPlace origin provenance rubric secFol signatures source stamp summary support surrogates textLang watermark
namesdates: addName affiliation age birth bloc country death district education faith floruit forename genName geogName langKnown nameLink nationality occupation orgName persName person placeName region residence roleName settlement sex socecStatus surname
nets: graph
spoken: u writing
tagdocs: valDesc
textcrit: app lem rdg wit witDetail
textstructure: argument back body byline closer dateline div div1 div2 div3 div4 div5 div6 div7 docAuthor docDate docEdition docImprint docTitle epigraph floatingText front group imprimatur opener postscript salute signed text titlePage titlePart trailer
transcr: damage fw restore supplied surplus
verse: metSym rhyme
可包含空白元素
宣告

<rng:element name="alt">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.linking.attributes"/>
 <rng:ref name="att.global.analytic.attributes"/>
 <rng:ref name="att.global.facs.attributes"/>
 <rng:ref name="att.pointing.attributes"/>
 <rng:ref name="att.typed.attributes"/>
 <rng:optional>
  <rng:attribute name="targets">
   <rng:list>
    <rng:ref name="data.pointer"/>
    <rng:ref name="data.pointer"/>
    <rng:zeroOrMore>
     <rng:ref name="data.pointer"/>
    </rng:zeroOrMore>
   </rng:list>
  </rng:attribute>
 </rng:optional>
 <rng:optional>
  <rng:attribute name="mode">
   <rng:choice>
    <rng:value>excl</rng:value>
    <rng:value>incl</rng:value>
   </rng:choice>
  </rng:attribute>
 </rng:optional>
 <rng:optional>
  <rng:attribute name="weights">
   <rng:list>
    <rng:ref name="data.probability"/>
    <rng:ref name="data.probability"/>
    <rng:zeroOrMore>
     <rng:ref name="data.probability"/>
    </rng:zeroOrMore>
   </rng:list>
  </rng:attribute>
 </rng:optional>
 <rng:empty/>
</rng:element>
element alt
{
   att.global.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.pointing.attributes,
   att.typed.attributes,
   attribute targets { list { data.pointer, data.pointer, data.pointer* } }?,
   attribute mode { "excl" | "incl" }?,
   attribute weights
   {
      list { data.probability, data.probability, data.probability* }
   }?,
   empty
}
Schematron

<s:report test="@target and @targets">You may not supply both
@target and @targets</s:report>
Schematron

<s:report test="not(@target) and not(@targets)">You must
supply either @target or @targets</s:report>
Schematron

<s:assert test="contains(@target,' ')">You must supply at least two
values for @target</s:assert>
例子
<alt mode="excl" targets="#we.fun #we.sun" weights="0.5 0.5"/>