Final answer:
The case of L'Estrange v Graucob (1934) demonstrates incorporation by signature, where signing a document binds someone to its terms, creating a contractual obligation.
Step-by-step explanation:
The case which illustrates incorporation by signature is L'Estrange v Graucob (1934). This case established the legal principle that when someone signs a contract, they are bound by its terms even if they have not read or understood them, assuming no misrepresentation or fraud. Incorporation by signature is a doctrine in contract law whereby signing a document signifies agreement with its terms, creating a binding obligation.