Journalist leads are a system of opening lead agreements vs. no-trump contracts:
Ace from a very strong holding that requests partner to unblock a top honor, if he has one. For example, leading the ace from AKJT5 asks partner to play the queen. Without an honor to unblock, partner should give a count signal instead.
King from AK(x) or KQ(x) asks partner to give an attitude signal. Note that a low card (e.g. fourth best) should be led from a long suit like AKxx or KQxxx if trying to establish the suit.
Queen from any suit headed by QJT or KQT9. The lead of the queen from KQT9 is now considered a standard lead. It asks partner to unblock the jack if he has it.
Jack from any suit headed by JT. The jack denies a higher honor, and is NOT led from interior sequences such as AJT9.
Ten from any interior sequences headed by the ten. Examples: AT95, KT98, QT954. The ten guarantees a higher non-touching honor, i.e. the ace, king or queen.
Nine from any suit headed by the T9. Examples: T95, T932.