CAS (Code Access Security)

<IPermission
class="AspNetHostingPermission"
version="1"
Level="Low"
/>

<IPermission
class="FileIOPermission"
version="1"
Unrestricted="true"
/>

Note this is roughly equivalent to High or Medium trust. Write FileIOPermission is only required if using user dictionaries, and can be restricted to the directory where the file is written, read permission is required if Dict File dictionaries are being used.