add note about ports

Author: mongoKart

source/fundamentals/authentication/ldap.txt

@@ -39,7 +39,8 @@ The code examples on this page use the following placeholders:
 - ``<password>``: Your LDAP password.
 - ``<hostname>``: The network address of your MongoDB deployment.
 - ``<port>``: The port number of your MongoDB deployment. If you omit this parameter,
-  the driver uses the default port number (``27017``).
+  the driver uses the default port number (``27017``). You don't need to specify a port
+  when connecting to a MongoDB Atlas cluster.
 - ``<authenticationDb>``: The MongoDB database that contains the user's LDAP credentials.
    If you omit this parameter, the driver uses the default database (``admin``).
 
@@ -62,7 +63,7 @@ see the corresponding syntax:
       .. code-block:: csharp
 
          var mongoClient = new MongoClient(
-            "mongodb://<username>:<password>@<hostname>/?authSource=<authenticationDb>" +
+            "mongodb://<username>:<password>@<hostname>[:<port>]/?authSource=<authenticationDb>" +
             "&authMechanism=PLAIN");
 
    .. tab:: MongoCredential

source/fundamentals/authentication/scram.txt

@@ -47,8 +47,9 @@ The code examples on this page use the following placeholders:
 
 - ``<db_username>``: The MongoDB username of the user to authenticate.
 - ``<db_password>``: The MongoDB password of the user to authenticate.
-- ``<hostname>``: The network address of the MongoDB deployment.
-- ``<port>``: The port number of the MongoDB deployment. You don't need a port number
+- ``<hostname>``: The network address of your MongoDB deployment.
+- ``<port>``: The port number of your MongoDB deployment. If you omit this parameter,
+  the driver uses the default port number (``27017``). You don't need a port number
   when connecting to a MongoDB Atlas cluster.
 - ``<authenticationDb>``: The MongoDB database that contains the user's authentication
   data. If you omit this parameter, the driver uses the default value, ``admin``.

source/fundamentals/authentication/x509.txt

@@ -40,7 +40,8 @@ The code examples on this page use the following placeholders:
 
 - ``<hostname>``: The network address of your MongoDB deployment.
 - ``<port>``: The port number of the MongoDB deployment. If you omit this parameter,
-  the driver uses the default port number (``27017``).
+  the driver uses the default port number (``27017``). You don't need a port number
+  when connecting to a MongoDB Atlas cluster.
 - ``<X.509 certificate username>``: The username of the user associated with the X.509
   certificate. The username must match the distinguished subject name of the certificate.
   If you omit this parameter, the MongoDB deployment infers the username