Meaning of "No instanceType" in AWS cost explorer report

Could someone help me in understanding the meaning of "No instance type" in the AWS Cost explorer report?

Solution

You will be charged for "no instance type" when you have terminated the EC2 instance but the resources related with that instance is not deleted/cleaned up like

Elastic IP addresses
Amazon Elastic Block Store (Amazon EBS) volumes etc..

Check if there are unused resources related to any previous instances that you created and terminated.

You could follow the steps mentioned in the article to clean up the common resources Here