A phenomenon you will come across during Tarot card study and Tarot readings are sub-elements and contradictory elements. Mainly associated with the Rider Waite-Smith Tarot deck and decks inspired by it, at its most simplistic explanation, sub-elements are those underlying elements that are secondary to the main one normally associated with a Tarot card. They can either compliment the main element and theme of the Tarot card, or they can in fact appear contradictory.
The Elemental Dignities Dictionary
Elemental Dignities Dictionary includes platonic solids, two card combinations, three card combinations, card pairing, two options spread, linear spread + tarot readings.