Del. Code tit. 16, § 3311

No dealer shall be prosecuted under this chapter when the dealer can establish a guaranty signed by the wholesaler, jobber, manufacturer or other party residing in the United States from whom the dealer purchases such articles to the effect that the same is not adulterated or misbranded within the meaning of this chapter. The guaranty, to afford protection, shall contain the name and address of the party making the sale of such articles to such dealer and, in such case, the party shall be amenable to the prosecutions, fines and other penalties which would attach, in due course, to the dealer under this chapter.