In the platform, Non-Recurring Costs are those costs for which the Item Description field has one of these values:
In addition, the platform looks at the product and usage_type columns to filter out any line items with the following values:
product = "PN_REDSHIFT" AND usage_type =~ "HeavyUsage"
product = "PN_RDS" AND description =~ "hourly fee per"
These two filters are used for RedShift All Upfront and RDS Heavy Reservation unused charges (Legacy type of RDS RI).