美国专利Claim中的substantially该如何解释？

see MPEP:
2173    Claims Must Particularly Point Out and Distinctly Claim the Invention [R-9]
D.   “Substantially”
The term “substantially” is often used in conjunction with another term to describe a particular characteristic of the claimed invention. It is a broad term. In reNehrenberg, 280 F.2d 161, 126 USPQ 383 (CCPA 1960). The court held that the limitation “to substantially increase the efficiency of the compound as a copper extractant” was definite in view of the general guidelines contained in the specification. In reMattison, 509 F.2d 563, 184 USPQ 484 (CCPA 1975). The court held that the limitation “which produces substantially equal E and H plane illumination patterns” was definite because one of ordinary skill in the art would know what was meant by “substantially equal.” Andrew Corp.v.Gabriel Electronics, 847 F.2d 819, 6 USPQ2d 2010 (Fed. Cir. 1988).
可见，之所以认为“substantially ”清楚，要么是因为说明书里有解释，要么是本领域有公知的理解。
我觉得“肉眼”看不靠谱，大家眼神不一样、认知不一样、对平行不平行的承受标准也不一样。建议还是去说明书里找找解释，或者在专利所在领域找找技术资料。

牛人啊，不服不行啊