連接詞"comprised of"

http://www.patenthawk.com/blog/2007/09/comprised_of_counterfeit.html
CIAS v. Alliance Gaming and Bally Gaming (CAFC 2006-1342)

These cases reflect the general understanding and usage of "comprised of" in patent convention as having the same meaning as "comprising." For patent claims the distinction between "comprising" and "consisting" is established, along with the meaning of "comprised of" as related to "comprising," not "consisting of." Correctly construed, "comprised of" does not of itself exclude the possible presence of additional elements or steps.

“comprised of ”為開放式的用語，不過，不太明白為什麼還是會有人使用這樣的字眼。會引起爭議的話，不用就好了不是嗎？