Update Doc/library/ipaddress.rst

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>

Author: mlnrt

Doc/library/ipaddress.rst

@@ -240,11 +240,16 @@ write code that handles both IP versions correctly.  Address objects are
 
    .. attribute:: is_reserved
 
-      ``True`` if the address is *labelled* as reserved by the IETF:
+      ``True`` if the address is noted as reserved by the IETF.
+      For IPv4, this is only ``240.0.0.0/4``, the "Reserved" address block.
+      For IPv6, this is all addresses `allocated <iana-ipv6-address-space_>`__ as
+      ``Reserved by IETF`` for future use.
 
-      * IPv4 address ``240.0.0.0/4`` named ``Reserved``. This attribute is not related to the
-        ``Reserved-by-Protocol`` value in iana-ipv4-special-registry_
-      * IPv6 addresses allocated as ``Reserved by IETF`` for future use (see iana-ipv6-address-space_)
+      Note: ``is_reserved`` is not related to the "Reserved-by-Protocol" value.
+
+      .. seealso::
+
+         iana-ipv4-special-registry_
 
    .. attribute:: is_loopback