Rule number 901 Minhaaj us Saaliheen 3
Kidneys, the two upper chambers of the heart, the veins, arteries, and
(perhaps the nerves because it is U'ROOQ as well), especially the jugular
vein, and its better to avoid the bones and the skin,
yes there is no problem in eating the skin of the head and the bird skin , and also in eating the bones of the small birds.
Safdar Razi Master