It is a report of analysis.
Certificate of Analysis (mostly chemicals) analysis report, quality inspection report COA is a quality inspection of the product before sale, the company's product qualification number of statistics, is to identify the product quality to meet the standard written proof. It is after the quality inspection of products, equipment, is to ensure that the product quality system standards.
Extended Information
Every new PC with genuine Windows operating system software preinstalled should contain a Certificate of Authenticity (COA) label. If the Windows OS software came with the purchase of the PC, the COA should be affixed to the PC chassis, as for flat panel PCs and other small devices, the COA label may be affixed under the battery.
If the Windows operating system software is not included with the purchase of a PC, but is sold in individual quantities in boxed retail software purchased through retail outlets and Microsoft resellers, the colorful box containing the licensed software should have a Certificate of Authenticity (COA) label attached to it.
Each Microsoft Certificate of Authenticity (COA) label contains a number of security features that help users ensure that they are obtaining genuine software. The product name and unique product key are displayed in the center of the label. Other features include a holographic band and color-changing film.
Baidu Encyclopedia-COA