What it means
Jyotish gives the 9th house to dharma: fortune, teachers, doing right. It gives the 10th to karma: work, action, public standing. Dharma-Karmadhipati yoga forms when their lords link up. Luck and effort then pull the same way. Many authors rank it as the finest of the raja yogas.
"Link" means one of three things: the two planets share a house, they exchange signs, or they look at each other. This rule asks for more than the textbook line. They must be two different planets, because one planet ruling both houses is a separate case. And neither lord can be debilitated or sitting in the 6th, 8th or 12th house.
About 1 chart in 7 passes. A looser version that accepts any kendra lord with any trikona lord passes more than half of all charts. That is why this one is narrow.
Read a pass as potential for status through work you believe in. A raja yoga does not switch on at birth. Tradition reads its timing from the dasha of the two planets. Find the planets, then look at their periods in your life.