VisualEditor's MWMathDialog has code such as this:
formulaCard = new OO.ui.CardLayout( 'formula', {
label: ve.msg( 'math-visualeditor-mwmathdialog-card-formula' ),
expandable: false,
scrollable: false,
padded: true
} );
optionsCard = new OO.ui.CardLayout( 'options', {
label: ve.msg( 'math-visualeditor-mwmathdialog-card-options' ),
expandable: false,
scrollable: false,
padded: true
} );
this.indexLayout.addCards( [
formulaCard,
optionsCard
] );This code uses the term "Card", which is usually used for a different UI concept. These tabs should be rather called Index, Panel, or Tab layout.
I spoke about this to Volker at the Dev Summit, and he may clarify this.