What are broken honor sequences?
KJT92-QT982-AJT9 or KT98. These are broken honor sequences. Leading from these sequences are not safe against suit contracts. They are attacking leads, usually against a No Trump contact. The standard accepted card to lead is "top of the interior sequence".
These leads are extremely helpful when dummy may hold an honor and one could trap a card in dummy, thus partner will not waste a higher card.
J43 (dummy)
K1098 (LHO) Q52 (RHO)
A76 (Declarer)
If LHO leads the ten, RHO will not waste the Queen, thus the Jack will not become a trick in dummy.
In No Trump contracts one requires 3 cards in a row touching each other, or nearly touching each other : QJ98 or J1087 as a sequence, thus leading the TOP card.