C is for Capital. The capital is the head of a column. C could also be for Corinthian, the particular style of the capital shown. You do not see too many homes these days being built with a lot of columns, but these same details are used on furniture as well.
D is for Dovetail. Dovetail is the interlocking of wedge shaped ends to form a joint. This construction method in furniture is a sure fire way of knowing it was made by someone or a company that believes in lasting quality. For example my cute modern dresser that was very well priced DOES NOT have dovetail joints and its veneer is already peeling off after just a few years.