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

card.portalID(posInteger)

card.portal(text)) // name

card.portal(posInteger) // number

background.portalID(posInteger)

background.portal(text)) // name

background.portal(posInteger) // number

For example:

thisCard.portalID(3)

thisCard.portal("Description")

thisCard.portal(1)

thisBackground.portal(2)