Clarify the rationale and motive for blanket IP banning and port exclusion

event-schemas/schema/m.room.server_acl

@@ -51,6 +51,10 @@ properties:
         description: |-
           True to allow server names that are IP address literals. False to
           deny. Defaults to true if missing or otherwise not a boolean.
+
+          This is strongly recommended to be set to ``false`` as servers running
+          with IP literal names are strongly discouraged in order to require 
+          legitimate homeservers to be backed by a valid registered domain name.
       allow:
         type: array
         description: |-

specification/modules/server_acls.rst

@@ -17,7 +17,7 @@ Server Access Control Lists (ACLs) for rooms
 
 .. _module:server-acls:
 
-In some scenarios room operators may wish to prevent a malicous or untrusted
+In some scenarios room operators may wish to prevent a malicious or untrusted
 server from participating in their room. Sending an `m.room.server_acl`_ state
 event into a room is an effective way to prevent the server from participating
 in the room at the federation level.
@@ -30,7 +30,10 @@ similar to setting the ``m.federate`` value on the `m.room.create`_ event.
 
 .. Note::
    Port numbers are not supported because it is unclear to parsers whether a
-   port number should be matched or an IP address literal.
+   port number should be matched or an IP address literal. Additionally, it
+   is unlikely that one would trust a server running on a particular domain's
+   port but not a different port, especially considering the server host can
+   easily change ports.
 
 .. Note::
    CIDR notation is not supported for IP addresses because Matrix does not