Ⓐ : Can be used aromatically
Ⓣ : Can be used topically
Ⓘ : Can be used internally
Ⓝ : Can be used topically no dilution
Ⓢ : Dilute for young or sensitive skin
Ⓓ : Dilute before using topically
Please note these are only a handful of common uses for each oil, there are many more.