The lead of an ace followed by the queen indicates the jack.
The lead of an ace followed by the jack indicates the ten, or no other card in the suit.
If it develops that your partner has led the ace from ace and two small cards, it indicates either a very weak hand or a tenace in some other suit.
The lead of a king indicates the ace, the queen, or both. Should the king win the first trick, you should infer that your partner holds the ace. If the king is taken by the ace, the queen is marked in your partner’s hand. If the king is followed by the ace, it denies the queen.
 | A K Q | |
| A K J | ||
| The king should be led from | A K x | |
| K Q J | ||
| K Q x |
The lead of a queen denies the ace and the king, consequently the lead places both of these high cards.
If a queen is led by your partner, you should infer that the lead is from jack ten; perhaps it would be better to say that the lead shows the jack. If you find the jack is either on the table or in your own hand, the lead was evidently from a short suit; queen and one or a singleton.
| The queen should be led from |  | Q J 10 |
| Q J 9 | ||
| Q J x | ||
| Q J | ||
| Q x | ||
| Q |
The lead of a jack denies the ace, the king, and the queen; consequently your partner holds no higher card of the suit; against a declared trump, it usually indicates a short suit.
There is some difference of opinion among Bridge players as to this lead; the jack is sometimes led from king queen jack, from king jack ten, and even from ace jack ten. The lead of a jack as the top card does away with the confusion that is caused by numerous interior leads. It simplifies the lead and facilitates the placing of higher cards.