Custom policies can be created as a supplement to the system policies of AOM.

You can create custom policies in either of the following two ways:

Visual editor: Select cloud services, actions, resources, and request conditions. This does not require knowledge of policy syntax.
JSON: Edit JSON policies from scratch or based on an existing policy.

For details about how to create custom policies, see Creating a Custom Policy. For example custom policies, see the following description.

Example Custom Policies

Example 1: Allowing a user to create threshold rules

{
    "Version": "1.1",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "aom:alarmRule:create"
            ]
        }
    ]
}

Example 2: Forbidding a user to delete application discovery rules
A deny policy must be used in conjunction with other policies to take effect. If the permissions assigned to a user contain both Allow and Deny actions, the Deny actions take precedence over the Allow actions.

To grant a user the AOM FullAccess system policy but forbid the user to delete application discovery rules, create a custom policy that denies the deletion of application discovery rules, and grant both the AOM FullAccess and deny policies to the user. Because the Deny action takes precedence, the user can perform all operations except deleting application discovery rules. The following is an example deny policy:
```
{
      "Version": "1.1",
      "Statement": [
            {
		  "Effect": "Deny",
                  "Action": [
                        "aom:discoveryRule:delete"
                  ]
            }
      ]
}
```

Example 3: Defining permissions for multiple services in a policy

A custom policy can contain actions of multiple services that are all of the project-level type. The following is an example policy containing actions of multiple services:

{
        "Version": "1.1",
        "Statement": [
                {
                        "Effect": "Allow",
                        "Action": [
                                "aom:*:list",
                                "aom:*:get",
                                "apm:*:list",
                                "apm:*:get"
                        ]
                },
                {
                         "Effect": "Allow",
                         "Action": [
                                 "cce:cluster:get",
                                 "cce:cluster:list",
                                 "cce:node:get",
                                 "cce:node:list"
                        ]
                }
        ]
}