MailAddress: Clarify formatting elements versus details of them. (#9837)

Author: breyed

xml/System.Net.Mail/MailAddress.xml

@@ -58,18 +58,20 @@ The <xref:System.Net.Mail.MailAddress> class is used by the <xref:System.Net.Mai
   
 A mail address is composed of a <xref:System.Net.Mail.MailAddress.User%2A> name, <xref:System.Net.Mail.MailAddress.Host%2A> name and optionally, a <xref:System.Net.Mail.MailAddress.DisplayName%2A>. The <xref:System.Net.Mail.MailAddress.DisplayName%2A> can contain non-ASCII characters if you encode them.  
   
-The <xref:System.Net.Mail.MailAddress> class supports the following mail address formats:  
+The <xref:System.Net.Mail.MailAddress> class supports the following mail address formats:
   
 -   A simple address format of `user@host`. If a <xref:System.Net.Mail.MailAddress.DisplayName%2A> is not set, this is the mail address format generated.  
   
 -   A standard quoted display name format of `"display name" <user@host>`. If a <xref:System.Net.Mail.MailAddress.DisplayName%2A> is set, this is the format generated.  
   
--   Angle brackets are added around the <xref:System.Net.Mail.MailAddress.User%2A> name and <xref:System.Net.Mail.MailAddress.Host%2A> name, if these are not included. For example, `"display name" user@host` is changed to `"display name" <user@host>`.
+    -   Angle brackets are added around the <xref:System.Net.Mail.MailAddress.User%2A> name and <xref:System.Net.Mail.MailAddress.Host%2A> name, if these are not included. For example, `"display name" user@host` is changed to `"display name" <user@host>`.
   
--   Quotes are added around the <xref:System.Net.Mail.MailAddress.DisplayName%2A>, if these are not included. For example, `display name <user@host>` is changed to `"display name" <user@host>`.
+    -   Quotes are added around the <xref:System.Net.Mail.MailAddress.DisplayName%2A>, if these are not included. For example, `display name <user@host>` is changed to `"display name" <user@host>`.
   
--   Unicode characters are supported in the <xref:System.Net.Mail.MailAddress.DisplayName%2A> property.  
+    -   Unicode characters are supported in the <xref:System.Net.Mail.MailAddress.DisplayName%2A> property.  
   
+Within these two formats, the following elements are allowed:
+
 -   A <xref:System.Net.Mail.MailAddress.User%2A> name with quotes. For example, `"user name"@host`.  
   
 -   Consecutive and trailing dots in user names. For example, `user...name..@host`.