更多关于美国食品标签方面法规，请详见 美国FDA 21 CFR 第101部分食品标签法规汇总
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§ 101.1 Principal display panel of package form food.
The term principal display panel as it applies to food in package form and as used in this part, means the part of a label that is most likely to be displayed, presented, shown, or examined under customary conditions of display for retail sale. The principal display panel shall be large enough to accommodate all the mandatory label information required to be placed thereon by this part with clarity and conspicuousness and without obscuring design, vignettes, or crowding. Where packages bear alternate principal display panels, information required to be placed on the principal display panel shall be duplicated on each principal display panel. For the purpose of obtaining uniform type size in declaring the quantity of contents for all packages of substantially the same size, the term area of the principal display panel means the area of the side or surface that bears the principal display panel, which area shall be:
（a） In the case of a rectangular package where one entire side properly can be considered to be the principal display panel side, the product of the height times the width of that side;
（b） In the case of a cylindrical or nearly cylindrical container, 40 percent of the product of the height of the container times the circumference;
（c） In the case of any otherwise shaped container, 40 percent of the total surface of the container: Provided, however, That where such container presents an obvious “principal display panel” such as the top of a triangular or circular package of cheese, the area shall consist of the entire top surface. In determining the area of the principal display panel, exclude tops, bottoms, flanges at tops and bottoms of cans, and shoulders and necks of bottles or jars. In the case of cylindrical or nearly cylindrical containers, information required by this part to appear on the principal display panel shall appear within that 40 percent of the circumference which is most likely to be displayed, presented, shown, or examined under customary conditions of display for retail sale.
§101.1 包装食品上的主要显示版面
本部分用于包装食品的名词"主要显示版面"，是指标签的一部分，是食品零售时在通常条件下最可能显示的、最容易观察到的部分。主要显示版面应有足够的大小以容纳本部分要求的、必须在这里标注的所有法定标注资料。要求标注清楚明了，不得带有模糊的图像和花饰，不显得拥挤。当包装上有多处主要显示版面时，凡要求在主要显示版面上显示的资料，必须在每个主要显示版面上作相同的显示。为了能在大小基本相同的所有包装上以统一的字体和大小标注内容物的数量，这里就"主要显示版面面积"加以界定。它是指主要显示版面中一个面的表面积，该面积必须为：
（a）对于一种长方形包装，可以考虑以一个完整侧面作为主要显示版面，面积为该侧面的高×宽的积。
（b）对于一种圆柱形或近似圆柱形的包装，则为容器的高×周长×40%。
（c）对于其它形状容器，则为容器总面积的40%；但是，倘若容器具有一个明显的"主要显示版面"，如干酪三角或圆形包装的顶部，其面积为整个顶部表面。在确定主要显示版面面积时，罐头的顶盖及底盖、顶盖及底盖凸缘、瓶子或罐的肩部和颈部面积不计算在内。对于圆柱形或近似圆柱形容器，本部分要求标注在主要显示版面上的资料必须显现在圆周的40%区域内，这个区域是零售商品在通常情况下最适于标注，最容易看到的部分。
