<form>

<form> (form information group) groups all the information on the written and spoken forms of one headword. [9.3.1 Information on Written and Spoken Forms]
Module dictionaries — Dictionaries
Attributes att.global (@xml:id, @n, @xml:lang, @xml:base, @xml:space) (att.global.rendition (@rend, @style, @rendition)) (att.global.linking (@corresp, @synch, @sameAs, @copyOf, @next, @prev, @exclude, @select)) (att.global.analytic (@ana)) (att.global.facs (@facs)) (att.global.change (@change)) (att.global.responsibility (@cert, @resp)) (att.global.source (@source)) att.lexicographic (@expand, @split, @value, @location, @mergedIn, @opt) (att.datcat (@datcat, @valueDatcat, @targetDatcat)) (att.lexicographic.normalized (@norm, @orig)) att.typed (type, @subtype)
type⚓︎ classifies form as simple, compound, etc.
Derived from att.typed
Status Optional
Datatype teidata.enumerated
Suggested values include:
simple
single free lexical item
lemma
the headword itself
variant
a variant form
compound
word formed from simple lexical items
derivative
word derived from headword
inflected
word in other than usual dictionary form
phrase
multiple-word lexical item
Member of
model.entryPart model.entryPart.top model.formPart
Contained by
core: cit
dictionaries: dictScrap entry entryFree form hom re sense superEntry
namesdates: nym
May contain
analysis: c cl interp interpGrp m pc phr s span spanGrp w
certainty: certainty precision respons
core: abbr add address bibl biblStruct binaryObject cb choice cit corr date del desc distinct ellipsis email emph expan foreign gap gb gloss graphic hi index label lb list listBibl measure measureGrp media mentioned milestone name note noteGrp num orig pb ptr q quote ref reg rs ruby said sic soCalled stage term time title unclear unit
dictionaries: case colloc form gen gram gramGrp hyph iType lang lbl mood number oRef orth pRef per pos pron stress subc syll tns usg
drama: camera caption castList move sound tech view
figures: figure formula notatedMusic table
gaiji: g
header: biblFull idno
iso-fs: fLib fs fvLib
linking: alt altGrp anchor join joinGrp link linkGrp seg timeline
msdescription: catchwords depth dim dimensions height heraldry locus locusGrp material msDesc objectType origDate origPlace secFol signatures stamp watermark width
namesdates: addName affiliation bloc climate country district forename genName geo geogFeat geogName listEvent listNym listObject listOrg listPerson listPlace listRelation location nameLink objectName offset orgName persName persPronouns placeName population region roleName settlement state surname terrain trait
spoken: incident kinesic pause shift vocal writing
tagdocs: att classSpec code constraintSpec dataSpec eg egXML elementSpec gi ident listRef macroSpec moduleSpec outputRendition specDesc specGrp specGrpRef specList tag val
textcrit: app listApp listWit witDetail
textstructure: floatingText
transcr: addSpan am damage damageSpan delSpan ex fw handShift listTranspose metamark mod redo restore retrace secl space subst substJoin supplied surplus undo
verse: caesura rhyme
character data
Example
<form>
 <orth>zaptié</orth>
 <orth>zaptyé</orth>
</form>

(from TLFi)
Content model 
<content>
 <alternate minOccurs="0"
  maxOccurs="unbounded">
  <textNode/>
  <classRef key="model.gLike"/>
  <classRef key="model.phrase"/>
  <classRef key="model.inter"/>
  <classRef key="model.formPart"/>
  <classRef key="model.global"/>
 </alternate>
</content>
Schema Declaration 
<rng:element name="form">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.global.rendition.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.global.change.attributes"/>
 <rng:ref name="att.global.responsibility.attributes"/>
 <rng:ref name="att.global.source.attributes"/>
 <rng:ref name="att.lexicographic.attributes"/>
 <rng:ref name="att.datcat.attributes"/>
 <rng:ref name="att.lexicographic.normalized.attributes"/>
 <rng:ref name="att.typed.attribute.subtype"/>
 <rng:optional>
  <rng:attribute name="type">
   <rng:choice>
    <rng:value>simple</rng:value>
    <rng:value>lemma</rng:value>
    <rng:value>variant</rng:value>
    <rng:value>compound</rng:value>
    <rng:value>derivative</rng:value>
    <rng:value>inflected</rng:value>
    <rng:value>phrase</rng:value>
    <rng:ref name="teidata.enumerated"/>
   </rng:choice>
  </rng:attribute>
 </rng:optional>
 <rng:zeroOrMore>
  <rng:choice>
   <rng:text/>
   <rng:ref name="model.gLike"/>
   <rng:ref name="model.phrase"/>
   <rng:ref name="model.inter"/>
   <rng:ref name="model.formPart"/>
   <rng:ref name="model.global"/>
  </rng:choice>
 </rng:zeroOrMore>
</rng:element>
element form
{
   att.global.attributes,
   att.global.rendition.attributes,
   att.global.linking.attributes,
   att.global.analytic.attributes,
   att.global.facs.attributes,
   att.global.change.attributes,
   att.global.responsibility.attributes,
   att.global.source.attributes,
   att.lexicographic.attributes,
   att.datcat.attributes,
   att.lexicographic.normalized.attributes,
   att.typed.attribute.subtype,
   attribute type
   {
      "simple"
    | "lemma"
    | "variant"
    | "compound"
    | "derivative"
    | "inflected"
    | "phrase"
    | teidata.enumerated
   }?,
   (
      text
    | model.gLike
    | model.phrase
    | model.inter
    | model.formPart
    | model.global
   )*
}