A - Anti-tragus - This piercing is through the thicker cartilage piece adjacent the tragus, attached to the rim of the ear.
C - Conch - also, conk. This term refers to any piercing through either the inner or outer shell of the ear.
D - Daith - This inner ear cartilage piercing is just above the opening into the ear canal. The name comes from the Hebrew word meaning wisdom.
H - Helix - Outer cartilage ridge piercings. This is a popular location for multiple rings, which can be set around the rim, or through the ridge itself.
L - Lobes, stretched - These are bigger gauge holes, usually lower down on the lobe. The smaller the jewelry gauge number, the larger the hole. Jewelry for these can be like tiny tubes or plugs and go up to about an inch and a half in the more commonly found largest sizes. Authentic, tribal jewelry is wearable in these sizes with elaborate, hand-carved pieces crafted from materials such as bone, stone or wood.
R - Rook - These ear piercings goes through the stiff ridge in the fold of the shell of the ear.
T - Tragus - This piercing is through the cartilage chunk just next to the opening of the ear canal. If you are fond of ear bud style head phones, be careful how you set this piercing, as placement deeper into the tissue or a larger gauge ring can interfere with how the buds seat themselves in the ear conch.
An Industrial is when multiple ear piercings are aligned so that one piece of jewelry, usually a barbell, is worn through the two holes. Helix piercings are easily paired this way, especially when the piercings are done specifically for this purpose but any two adjacent piercings that can be comfortabley connected will work. This style has also been called an Ear Orbit when it is done so that a ring is worn through the two holes.
A Transverse piercing runs across the length of the lobe, rather than through it, like a surface piercing on the ear. Placement of this unique piercing usually works best on the lower lobe where the tissue is both flat and flexible.