For the purposes of these standards, the following terms shall have the meanings stated below:

(a) Broken kernels. Kernels of rice which are less than three-fourths of whole kernels.

(b) Chalky kernels. Whole or large broken kernels of rice which are one-half or more chalky.

(c) Classes. The following four classes:

(1) “Long grain rough rice” shall consist of rough rice which contains more than 25 percent of whole kernels and which after milling to a well-milled degree, contains not more than 10 percent of whole or broken kernels of medium or short grain rice.

(2) “Medium grain rough rice” shall consist of rough rice which contains more than 25 percent of whole kernels and which after milling to a well-milled degree, contains not more than 10 percent of whole or large broken kernels of long grain rice or whole kernels of short grain rice.

(3) “Short grain rough rice” shall consist of rough rice which contains more than 25 percent of whole kernels and which, after milling to a well-milled degree, contains not more than 10 percent of whole or large broken kernels of long grain rice or whole kernels of medium grain rice.

(4) “Mixed rough rice” shall consist of rough rice which contains more than 25 percent of whole kernels and which, after milling to a well-milled degree, contains more than 10 percent of “other types” as defined in paragraph (h) of this section.

(d) Damaged kernels. Whole or broken kernels of rice which are distinctly discolored or damaged by water, insects, heat, or any other means, and whole or large broken kernels of parboiled rice in non-parboiled rice. “Heat-damaged kernels” (see paragraph (e) of this section) shall not function as damaged kernels.

(e) Heat-damaged kernels. Whole or large broken kernels of rice which are materially discolored and damaged as a result of heating, and whole or large broken kernels of parboiled rice in nonparboiled rice which are as dark as, or darker in color than, the interpretive line for heat-damaged kernels.

(f) Milling yield. An estimate of the quantity of whole kernels and total milled rice (whole and broken kernels combined) that are produced in the milling of rough rice to a well-milled degree.

(g) Objectionable seeds. Seeds other than rice, except seeds of Echinochloa crusgalli (commonly known as barnyard grass, watergrass, and Japanese millet).

(h) Other types. (1) Whole kernels of:

(i) Long grain rice in medium or short grain rice,

(ii) Medium grain rice in long or short grain rice,

(iii) Short grain rice in long or medium grain rice, and

(2) Large broken kernels of long grain rice in medium or short grain rice and large broken kernels of medium or short grain rice in long grain rice.

(i) Paddy kernels. Whole or broken unhulled kernels of rice.

(j) Red rice. Whole or large broken kernels of rice on which there is an appreciable amount of red bran.

(k) Seeds. Whole or broken seeds of any plant other than rice.

(l) Smutty kernels. Whole or broken kernels of rice which are distinctly infected by smut.

(m) Types of rice. The following three types:

(n) Ungelatinized kernels. Whole or large broken kernels of parboiled rice with distinct white or chalky areas due to incomplete gelatinization of the starch.

(o) Whole and large broken kernels. Rice (including seeds) that (1) passes over a 6 plate (for southern production), or (2) remains on top of a 6 sieve (for western production).

(p) Whole kernels. Unbroken kernels of rice and broken kernels of rice which are at least three-fourths of an unbroken kernel.

(q) 6 sieve. A metal sieve 0.032-inch thick, perforated with rows of round holes 0.0938 ( 6/64) inch in diameter.

(r) 6 plate. A laminated metal plate 0.142-inch thick, with a top lamina 0.051-inch thick, perforated with rows of round holes 0.0938 ( 6/64) inch in diameter, and a bottom lamina 0.091-inch thick, without perforations.