6.2 Acts, Scenes, and Classical Scenes

6.2.1 SGML

Consider using <plydv1 type="act" n=""> and <classscen=""> tags to mark these features. Note that classical scenes are always bounded by a character's entrance or exit, which may occur in the middle of speeches or even lines. Thus the classscen element would not usually be an attribute of a <plydv2 type="scene" scenen="" classenn=""> tag because two scenes may share one classical scene, and one scene may have multiple classical scenes.
<plydv1 type="act" n="1">A{ct}us Primus.
  <plydv2 type="scene" n="1"
  classcene="1">Sc{oe}na Prima.

6.2.2 COCOA

Consider using <act>, <scene>, <actscene>, and <classscene> to tag the following text with the number of those units, and then precede the original text indicating act and scene information with <tt act> and <tt scene>.
<act 1>
<scene 1>
<actscene 1.1><classscene 1>
<tt act><f i>Actus  Primus. <tt scene>Scoena Prima.<f r>
<tt stage>