Specially mention super().__new__()

Clarify that inheriting from a protocol makes it behave like a nominal class (wrt ReadOnly)

Author: Enegg

peps/pep-0767.rst

@@ -281,9 +281,12 @@ Assignment to a read-only instance attribute must be allowed in the following co
 
 * In ``__init__``, on the instance of the declaring class received as
   the first parameter (usually ``self``).
-* In ``__new__`` and ``@classmethod``\ s, on instances of the declaring class
-  created via a call to ``__new__`` on any object of type ``type[T]``, where
-  ``T`` is a *nominal supertype* of the declaring class.
+* In ``__new__`` and ``@classmethod``\ s, on instances of the declaring class created via:
+
+  - a call to ``super().__new__()``,
+  - a call to ``__new__`` on any object of type ``type[T]``,
+    where ``T`` is a *nominal supertype* of the declaring class.
+
 * At declaration in the class scope.
 
 Additionally, a type checker may choose to allow the assignment
@@ -421,6 +424,12 @@ is assignable to ``T``:
 
 Read-only protocol attributes may not be assigned to or deleted in any context.
 
+Note that when inheriting from a protocol to `explicitly declare its implementation <https://typing.python.org/en/latest/spec/protocol.html#explicitly-declaring-implementation>`__,
+for the purpose of applying rules regarding read-only attributes (that the protocol may define),
+the protocol should be treated as if it was a nominal class.
+In particular, this means that subclasses *can* initialize read-only attributes
+that have been defined by the protocol.
+
 Type checkers should not assume that access to a protocol's read-only attributes
 is supported by the protocol's type (``type[HasName]``). Even if an attribute
 exists on the protocol's type, no assumptions should be made about its type.
@@ -436,8 +445,8 @@ Subtyping
 The inability to assign to or delete read-only attributes makes them covariant.
 This has a few subtyping implications. Borrowing from :pep:`705#inheritance`:
 
-* Read-only attributes can be redeclared as writable attributes, descriptors
-  or class variables::
+* Read-only attributes can be redeclared by a subclass as writable attributes,
+  descriptors or class variables::
 
     @dataclass
     class HasTitle: