[Property Name] Sandboxed Solution [Description] 
Specifies whether the project should be deployed as a sandboxed solution, also known as a user-created solution. Sandboxed solutions are not necessarily trustworthy. A value of true means that the project is deployed as a sandboxed solution, a value of false means that the project is deployed as a farm solution. For more information, see Sandboxed Solution Considerations and Differences Between Sandboxed and Farm Solutions.