An expression that identifies a card by name, number, or id, using one of the following forms:

back                                    ordinalMarkedCard

cardID(posInteger)                      positionMarkedCard

[background].card(text) // name         markedCard(posInteger)

card(posInteger) // number

[background].ordinalCard

[background].positionCard

For example:

cardID(3894)                            firstMarkedCard

card("index")                           lastMarkedCard

background(1).card(1)                   nextMarkedCard

previousCard                            previousMarkedCard

thisCard                                markedCard(1)

firstCard