Imperial

The Imperial was a form of currency.

Aldo, a member of Rorvik's crew, was seen to flip a 100 Imperials coin aboard the privateer ship.

When the TARDIS entered a time rift, the Fourth Doctor and Romana II argued about what they should do next. When Romana facetiously made the suggestion that they should flip a coin to decide, a method with which the Doctor didn't see anything wrong, Adric took the remark seriously and flipped a coin — possibly another 100 Imperials piece — to decide whether to operate a random control on the console. (TV: Warriors' Gate)

Behind the scenes

 * There is no close-up of the coin which Adric flips in Warriors' Gate part one, and he never identifies this particular piece of currency by name.