A 'full set' or 'complete set' means a bag is accompanied by all its original accessories: the branded box, dust bag, authenticity card (for brands that include one), original receipt, and any items that came with the bag — additional straps, pouches, or mirror bags.
A full set adds meaningful resale value — typically 10–20% above the same bag without its accessories. It also provides provenance: the receipt confirms the purchase price, date, and location. For bags where the original purchase price matters (like Chanel, which uses price-linked authentication), having the original receipt is particularly valuable.