minor fix about visibility in reference
@@ -1731,7 +1731,8 @@ of an item to see whether it should be allowed or not. This is where privacy
warnings are generated, or otherwise "you used a private item of another module
and weren't allowed to."
-By default, everything in Rust is *private*, with one exception. Enum variants
+By default, everything in Rust is *private*, with two exceptions: Associated
+items of a Trait are public by default; Enum variants
in a `pub` enum are also public by default. When an item is declared as `pub`,
it can be thought of as being accessible to the outside world. For example:
