在添加各种自定义的权限时，请遵循如下基本原则：
- If you create a new content type with a custom "add" permission, you
should normally grant this to the Contributor role globally, using
rolemap.xml.
- Similarly, if you have any custom permissions necessary to view an object, they should normally be granted to the Reader role,
- whilst any permissions necessary to modify an object should be granted to the Editor role.