Note to Paragraph (b): A carat is a standard unit of weight for a diamond and is equivalent to 200 milligrams (1/5 gram). A point is one one-hundredth (1/100) of a carat.
Note to Paragraph (d): When fractional representations of diamond weight are made, as described in paragraph (d) of this section, in catalogs or other printed materials, the disclosure of the fact that the actual diamond weight is within a specified range should be made conspicuously on every page where a fractional representation is made. Such disclosure may refer to a chart or other detailed explanation of the actual ranges used. For example, "Diamond weights are not exact; see chart on p. X for ranges."
16 C.F.R. §23.18