Refer to the return value on nameindex and friends as a string, not a byte
string.  The code was fixed to return strings instead of bytes and to accept
either.
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index 5b2e6bd..7ce7705 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -539,7 +539,7 @@
 .. function:: if_nameindex()
 
    Returns a list of network interface information
-   (index, name as a byte string) tuples.
+   (index, name as a string) tuples.
    :exc:`socket.error` if the system call fails for any reason.
 
    Availability: Unix.
@@ -550,7 +550,7 @@
 .. function:: if_nametoindex(if_name)
 
    Returns a network interface index number corresponding to an
-   interface name byte string.
+   interface name string.
    :exc:`socket.error` if no interface with the given name exists.
 
    Availability: Unix.
@@ -560,7 +560,7 @@
 
 .. function:: if_indextoname(if_index)
 
-   Returns a network interface name byte string corresponding to a
+   Returns a network interface name string corresponding to a
    interface index.
    :exc:`socket.error` if no interface with the given index exists.