A functional specification describes how a product will work entirely from the user's perspective. It doesn't care how the thing is implemented. It talks about features. It specifies screens, menus, dialogs, and so on - joelonsoftware.com 
# Overview Liquid Wiki is - Scenarios - Non Goals - Flowchart - Screen by Screen Specification
# Examples
This is a summary of the functional specification for Version 1 of the SivaSiva Book Module.
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