[css-fonts-4] Add issue about oblique search threshold. w3c#2295

Author: fantasai

css-fonts-4/Overview.bs

@@ -672,6 +672,9 @@ Font style: the 'font-style!!property' property</h3>
     the <code>slnt</code> variation is used to implement oblique values,
     and the <code>ital</code> variation with a value of 1 is used to implement the italic values.
 
+    ISSUE: The threshold for preferring oblique over normal
+    <a href="https://github.com/w3c/csswg-drafts/issues/2295">should be lower than the average angle</a>.
+
     Issue: What direction should positive and negative obliques skew in vertical writing mode?
     How do we achieve skews in the opposite dimension
     (needed for vertical writing)?
@@ -2580,6 +2583,9 @@ if all font style properties were set to their initial value.
 				3. If no match is found, oblique values greater than or equal to 20deg are checked in ascending order
 					followed by oblique values below 20deg in descending order, until 0 is hit. Only positive values of oblique values
 					are checked in this stage.
+
+					ISSUE: The threshold for preferring oblique over normal <a href="https://github.com/w3c/csswg-drafts/issues/2295">should be lower than the average angle</a>.
+
 				4. If no match is found, italic values less than or equal to 0 are checked in descending order until a match is found.
 				5. If no match is found, oblique values less than or equal to 0deg are checked in descending order until a match is found.