The order of taxa in biology: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species:

 Mnemonic:
"Dear King Philip Come Over For Good Spaghetti/Soup" is often cited as a (clean) method for teaching students to memorize the taxonomic classification system. Other variations tend to start with the mythical king, with one author noting "The nonsense about King Philip, or some ribald version of it, has been memorized by generations of biology students."

 Mnemonic:
Do Kings Play Chess On Fat Green Stools?

 Mnemonic:
Do Kings Play Chess On Fine Green Silk?

 Mnemonic:
Dumb Kids Prefer Candy Over Fancy Green Salad

 Mnemonic:
Dumb Kids Playing Catch On Freeway Get Squashed

 Mnemonic:
Dirty, Kinky People Can Often Find Great Sex

 Mnemonic:
Do Kids Pass Chemistry Or Flunk General Science?

 Mnemonic:
Does King Phillp Come Over For Grape Soda