Fields that contain special characters

If a field contains non-alphanumeric characters other than the @ symbol or the period (.), you must surround the field with backtick characters (`). For example, the log field foo-bar must be enclosed in backticks (`foo-bar`) because it contains a non-alphanumeric character, the hyphen (-).

For system fields that start with @ and contain special characters in the remaining name, place the @ symbol outside the backticks and enclose only the field name portion. For example, resource tag fields use the pattern @aws.tag.<tagKey>. If the tag key contains special characters such as colons, you must use the following syntax:

@`aws.tag.aws:cloudformation:stack-name`

The following example shows a filter query that uses this syntax:

filter @`aws.tag.aws:cloudformation:stack-name` = "my-stack"