Update APCA_in_a_Nutshell.md

Author: Myndex

documentation/APCA_in_a_Nutshell.md

@@ -20,22 +20,23 @@ This points to the importance of real user personalization, an area where the te
 ## Use-Case & Size Ranges
 These general levels are appropriate for use by themselves, without the need to reference a lookup table. APCA reports contrast as an Lc value (lightness contrast) from **Lc 0** to **Lc 105+**. For accessibility, consider Lc 15 the point of invisibility for many users, and Lc 90 is preferred for body text.
 
-*   **Lc 90** • Preferred level for fluent text and columns of body text with a font no smaller than 18px/weight 300 or 14px/weight 400 (normal), or non-body text with a font no smaller than 12px. Also a recommended minimum for extremely thin fonts with a minimum of 24px at weight 200. Lc 90 is a _suggested maximum_ for **very large and bold fonts** (greater than 36px bold), and large areas of color.
+*   **Lc 90** • Preferred level for fluent text and columns of body text with a font no smaller than 18px/weight 300 or 14px/weight 400 (normal), or non-body text with a font no smaller than 12px/400. Also a recommended minimum for extremely thin fonts with a minimum of 24px at weight 200. Lc 90 is a _suggested maximum_ for **very large and bold fonts** (greater than 36px bold), and large areas of color. Small fonts do not have a maximum.
 *   **Lc 75** • The _minimum_ level for columns of body text with a font no smaller than 24px/300 weight, 18px/400, 16px/500 and 14px/700. This level may be used with non-body text with a font no smaller than 15px/400. Also, Lc 75 should be considered a minimum for larger for any larger text where readability is important.
 *   **Lc 60** • The _minimum_ level recommended for content text that is not body, column, or block text. In other words, text you want people to read. The minimums: no smaller than 48px/200, 36px/300, 24px normal weight (400), 21px/500, 18px/600, 16px/700 (bold). These values based on the reference font Helvetica. To use these sizes as body text, add Lc 15.
 *   **Lc 45** • The _minimum_ for larger, heavier text (36px normal weight or 24px bold) such as headlines, and large text that should be fluently readabile but is not body text. This is also the minimum for pictograms with fine details, or smaller outline icons.
-*   **Lc 30** • The _absolute minimum_ for any text not listed above, including text considered as "spot readable". This includes placeholder text and disabled element text, and some non-content like a copyright bug. This is also the minimum for large/solid semantic & understandable non-text elements such as "mostly solid" icons or pictograms. Generally no less than 4px in its smallest dimension.
-*   **Lc 15** • The _absolute minimum_ for any non-text that needs to be _discernible_ and differentiable, and is no less than 6px in its smallest dimention. This may include dividers, and in _some_ cases large buttons or thick focus visible outlines, but does _not_ include fine details which have a higher minimum. **Designers should treat anything below this level as invisible**, as it will not be visible for many users. This minimum level should be avoided for any items important to the use, understanding, or interaction of the site.
+*   **Lc 30** • The _absolute minimum_ for any text not listed above, including text considered as "spot readable". This includes placeholder text and disabled element text, and some non-content like a copyright bug. This is also the minimum for large/solid semantic & understandable non-text elements such as "mostly solid" icons or pictograms. Generally no less than 4px solid in its smallest dimension.
+*   **Lc 15** • The _absolute minimum_ for any non-text that needs to be _discernible_, and is no less than 6px (solid) in its smallest dimention. This may include dividers, and in _some_ cases large buttons or thick focus visible outlines, but does _not_ include fine details which have a higher minimum. **Designers should treat anything below this level as invisible**, as it will not be visible for many users. This minimum level should be avoided for any items important to the use, understanding, or interaction of the site.
 
-These define the basic minimum levels, what you might think of as A/AA in the old WCAG 2. For the equivelent to AAA, simply increase the contrast values by Lc 15.
+These define the basic minimum levels, what you might think of as AA in the old WCAG 2. For the equivelent to AAA, simply increase the contrast values by Lc 15.
 
 **_NOTES ON FONT SIZE_**
-- Font sizes listed above assume an x-height ratio of at least 0.52. Font weight is based on highly standardized reference fonts such as Helvetica or Arial. "px" means the CSS reference px, not device pixels. The reference px is defined as 1.278 arc minutes of visual angle.
+- Font sizes listed above assume an x-height ratio of 0.5. Font weight is based on highly standardized reference fonts such as Helvetica or Arial. "px" means the CSS reference px, not device pixels. One reference px is defined as 1.278 arc minutes of visual angle.
 - When selecting, or testing, a font size, all that needs to be done is to compare the x-height to the reference.
     - For instance Times New Roman has an x-height ratio of 0.45, so it needs to be increased about 16% in size.
 - For font weight, simply set a line of test text in the reference Arial or Helvetical at 400 weight and then below that the same text text in the new font. Try different weights to find the closest match.
     - As an example, the font Raleway 400 weight is closest to Helvetica 300.
-    - So, always add 100 in weight to Raleway to be equivelent.
+    - So, add 100 in weight to Raleway to be equivelent.
+    - Note that some fonts change weight differently, and should be compared at other weights, such as 700, if those weights are to be used.
     - See [this discussion answer](https://github.com/Myndex/SAPC-APCA/discussions/28#discussioncomment-1610289) for more.
 - Consider the font design as well as the basic size and weight, and the potential impact on readability. See [this PDF **"Evaluating Fonts"**](https://www.researchgate.net/publication/338149302_Evaluating_Fonts_Font_Family_Selection_for_Accessibility_Display_Readability) for general guidance and a comparison of a few dozen fonts for accessibility.