Introduction:
The doctrine of caveat emptor is a principle that states that the buyer is responsible for conducting their own due diligence and is required to be cautious and aware of any potential defects or issues with the goods they are purchasing. However, there are certain situations where this principle does not apply.

Goods purchased by sample:
When goods are purchased by sample, it means that the buyer has the opportunity to examine and evaluate a sample of the goods before making the purchase. In such cases, the buyer relies on the sample as a representation of the entire batch of goods. If the goods delivered do not match the sample provided, the doctrine of caveat emptor does not apply. The seller is deemed to have made a guarantee that the goods will be of the same quality and characteristics as the sample.

Goods purchased by sample and description:
Similarly, when goods are purchased by sample and description, the buyer not only relies on the sample but also on the description provided by the seller. If the goods delivered do not match the sample or do not meet the description provided, the doctrine of caveat emptor does not apply. The seller is considered to have made a guarantee that the goods will conform to both the sample and the description given.

Goods purchased under its brand name:
When goods are purchased under their brand name, it implies that the buyer is placing trust in the reputation and quality associated with that brand. In such cases, if the goods turn out to be defective or not up to the expected standard, the doctrine of caveat emptor does not apply. The buyer can hold the brand responsible for any issues or defects in the goods purchased.

Conclusion:
In summary, the doctrine of caveat emptor does not apply when goods are purchased by sample, goods are purchased by sample and description, and goods are purchased under their brand name. In these situations, the buyer has relied on certain representations made by the seller, and if the goods do not meet those representations, the buyer is entitled to seek remedies and hold the seller accountable. It is important for buyers to be aware of their rights and the exceptions to the doctrine of caveat emptor in order to protect themselves when making purchases.