TestLink

Is there a Data Flow Diagram documentation available for Testlink 1.9 ?

I have tried to update Testlink verion 1.9 Test Execution document to include 'Test Result' column per test step using custom link function(drop down listbox that contains PASS/FAIL selection) . The column appears now next to execution type and I can update the document with the result per test step...

My company would like to study Testlink and its possibility to be used to support our processes.
Is there available flowchart, ERD, or other design documents that can be accessed to aid our study?

-And is there a User Manual for Testlink 1.9 planned to be released soon?