In all cases, a Permission (ie, a class that descends from System.Security.CodeAccessPermission) has at least two modes: Unrestricted, or Restricted.

An example of such a simple Permission would be the DnsPermission (which only has two states: Unrestricted, or Restricted).

But most of the of the Permissions, if they are not in the Unrestricted mode, work with Enums instead:

Permission Options

Some of the more common options (and notes about their usage where needed) are listed below:

• System.Security.Permissions.EnvironmentPermission:
  • Unrestricted, or
  • One or more environment variable names, each with one or more of the following:
    • Read,
    • Write
• System.Security.Permissions.FileDialogPermission:
  • Unrestricted, or
  • One of the following:
    • Open,
    • Save,
    • Open&Save,
    • None
• System.Security.Permissions.FileIOPermission:
  • Unrestricted, or
  • A list of one or more paths, each with one or more of the following:
    • Read
    • Write
    • Append
    • Path Disc.
• System.Security.Permissions.IsolatedStoragePermission: (abstract ) && System.Security.Permissions.IsolatedStorageFilePermission:
• Unrestricted, or
• One of the following:
• None,
• Administer Isolated storage by User
• Assembly Isolation by User
• Assembly Isolation by Roaming User, 
• Domain Isolation by User,
• Domain Isolation by Roaming User,
• System.Security.Permissions.ReflectionPermission:
  • Unrestricted, or
  • One or more of the following:
    • Member: Assemblies can discover member information in other assemblies. Members include the methods and properties within the classes that contain Assemblies.
    • Type: Assemblies can discover Type information in other assemblies. Types include the methods and properties within the classes that contain Assemblies.
    • Emit: Script engines and compilers are allowed to generate assemblies.
• System.Security.Permissions.RegistryPermission:
  • Unrestricted, or
  • One or more of:
    • Read,
    • Write,
    • Create
• System.Security.Permissions.UIPermission:
• The permission to use windows can be one of the following: unrestricted, limited to SafeTopLevelWindows, only SafeSubWindows, or no window drawing or user input event access allowed. SafeTopLevelWindows and SafeSubWindows are restricted in title and size to prevent possible spoofing by potentially harmful code.
• The permission to use the clipboard can be one of the following: unrestricted, write-only, or no clipboard access allowed. The paste limitation prevents potentially harmful applications from taking data from the clipboard without the user's consent, while still allowing the cut, copy, and paste operations when initiated by the user through keyboard commands.

• Unrestricted, or:
  • Interface Elements:
    • All windows and events
    • Safe TopWindows
    • Safe SubWindows
    • None
  • Clipboard
    • None,
    • Own,
    • All

• System.Net.DNSPermission:
  Note: Default allows Intranet Zone applications to access DNS services, but not for Internet Zone.
  
  • Unrestricted (ie 'Yes'), or
  • Restricted  (ie 'No')
    
• System.Drawing.Printing.PrintingPermission:
  • Unrestricted, or
  • One of the following:
    • None
    • Safe
    • Default
    • All
• SecurityPermission [see above]
• System.Net.SocketPermission:
  • Unrestricted, or
  • Restricted to a given list of one or more entries, each with one or more of the following properties defined:
    • Host,
    • Post,
    • Incoming/Outgoing,
    • TCP/UDP
• System.Net.WebPermission:
  • Unrestricted, or
  • Restricted to a given list of one or more entries, each with one or more of the following properties defined:
    • Host,
    • Accept/Connect
• System.Diagnostics.EventLog:
  • Unrestricted, or
  • One of the following:
    • None,
    • Browse,
    • Instrument
    • Audit
• System.Diagnostics.PerformanceCounter:
  • Unrestricted, or
  • One of the following settings:
    • None
    • Browse
    • Instrument
• System.DirectoryServices.DirectoryServicesPermission:
  • Unrestricted, or
  • One of the following settings:
    • None
    • Browse
• System.Messageing.MessageQueue:
  • Unrestricted, or
  • Or ...