Hi Ernst,
In the book "Vault of the Heavens", on page 272 Ch Judging the Horoscope, it says
"The Karaka is the planet that is the causer/producer of the item under consideration, the house gives birth to the item, and the house lord is the item under consideration in its activities"
Should that be
The Karaka is the planet that is the causer/producer of the item under consideration, the house gives birth to the item, and the house lord has the item under consideration in its activities
And by "item under consideration", do we mean the "signification under consideration"?
How I would see it now is that the karaka is the producer, the maker. The bhava is the concrete thing. The lord is the consciousness that is experiencing and managing the thing.
The producer is mars, the producer is always the Karaka.
Then there are the minifestors, those are the lord, Jupiter and Mercury. These manifest a bhava, bring it into existence.
Then there are the conditioners, which are all the planets, so in this case, Venus is conditioning the real estate to be Venusian.