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 **Work In Progress**
 
+## Preface
+
+The final goal of this repository is making a viable solution for programmer,
+who is familiar with GUI application development on POSIX system
+and want to find a workable way to setup file associations on Windows for their developed software
+without learning too much Win32 knowledge.
+
+So considering this premise, this library will NOT assist those professional Windows developer
+for setting up those complex Windows shell functions, such as the interaction with Explorer preview panel,
+or adding extra entries in menu.
+
+In brief words, this library only do one thing. Setup and check file associations for your application,
+and make it at least works.
+
 ## Introduction
 
 * `wfassoc`: Core Rust library. Rust programmer can directly utilize it.