[css-text-3] Define ‘word separator’ a bit more precisely. #3878

Author: fantasai

css-text-3/Overview.bs

@@ -4740,8 +4740,9 @@ Word Spacing: the 'word-spacing' property</h3>
     </wpt>
 
     <p><dfn id="word-separator" lt="word-separator character | word separator">Word-separator characters</dfn>
-      are <a>typographic character units</a> whose purpose and general usage is to separate words.
-      In [[UNICODE]] this includes
+      are <a>typographic character units</a>
+      whose primary purpose and general usage is to separate words.
+      In [[UNICODE]] this includes (but is not exhaustively defined as)
       the space (U+0020), the no-break space (U+00A0), the Ethiopic word space (U+1361),
       the Aegean word separators (U+10100,U+10101), the Ugaritic word divider (U+1039F),
       and the Phoenician Word Separator (U+1091F).
@@ -4759,9 +4760,11 @@ Word Spacing: the 'word-spacing' property</h3>
           word-spacing-characters-003.xht
       </wpt>
 
-      General punctuation
-      and fixed-width spaces (such as U+3000 and U+2000 through U+200A)
-      are not considered [=word-separator characters=].
+      Note: Neither punctuation in general,
+      nor fixed-width spaces (such as U+3000 and U+2000 through U+200A),
+      are considered [=word-separator characters=],
+      because even though they frequently happen to separate words,
+      their primary purpose is not to separate words.
 
       <wpt pathprefix="css/CSS2/text">
           word-spacing-characters-002.xht