Coin collecting of investment, the principle of "caveat emptor" applies and study is recommended before buying. Likewise, as with most collectibles, a coin collection does not produce income until it is sold, and may even incur costs (for example, the cost of safe deposit box storage) in the interim. Coin hoarders may be similar to investors in the sense that they accumulate coins for potential long-term profit. However, unlike investors, they typically do not take into account aesthetic considerations; rather they gather whatever quantity of coins they can and hold them. This is most common with coins whose metal value exceeds their
Patent caveat as the proposed patent, the Patent Office notified the holder of the caveat, who then had three months to submit a formal patent application with claims. If the two patent applications claimed the same invention, an interference would then be declared and neither patent could be issued until it was determined which was the first to invent. Perhaps the most famous example of such a conflict was on 14 February 1876, when Elisha Gray filed a patent caveat and Alexander Graham Bell filed a patent application on the same day, both relating to the telephone. Gray ended up abandoning his