These territories are sometimes referred to as the Països Catalans (Catalan Countries), a denomination based on cultural affinity and common heritage, that has also had a subsequent political interpretation but no official status. Various interpretations of the term may include some or all of these regions.
What is that determination based on?
cultural affinity and common heritage

The staple foods were generally consumed around 11 o'clock, and consisted of bread, lettuce, cheese, fruits, nuts, and cold meat left over from the dinner the night before.[citation needed] The Roman poet Horace mentions another Roman favorite, the olive, in reference to his own diet, which he describes as very simple: "As for me, olives, endives, and smooth mallows provide sustenance." The family ate together, sitting on stools around a table. Fingers were used to eat solid foods and spoons were used for soups.[citation needed]
What form of expression did the Roman Horace practice?
poet

Contract law covers obligations established by agreement (express or implied) between private parties. Generally, contract law in transactions involving the sale of goods has become highly standardized nationwide as a result of the widespread adoption of the Uniform Commercial Code. However, there is still significant diversity in the interpretation of other kinds of contracts, depending upon the extent to which a given state has codified its common law of contracts or adopted portions of the Restatement (Second) of Contracts.
What standardized contract law?
Uniform Commercial Code