Fields that contain special characters - Amazon CloudWatch Logs
Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Fields that contain special characters

You must surround log fields named in queries that include characters other than the @ symbol, period (.), and non-alphanumeric characters in backtick keys (`). For example, the log field foo-bar must be enclosed in backticks (`foo-bar`) because it contains a non-alphanumeric character, the hyphen (-).