The 
 Plug-In DLL defines all the interfaces supported and entry-points published 
 by the Codex Plug-In. In addition to the DLL, a number of auxiliary profile 
 and directive files are used.
The Plug-In DLL exports a number of functions which provide archive services 
 to Codex applications. These functions are enumerated below:
GetArchiveInfo
GetArchiveSizeEx
GetArchiveInfoEx
GetArchiveError
GetArchiveErrorEx
ShowPlugInAbout
CodexStandardFunction
The plug-in also needs to understand the formats of various directive files 
 used by Codex and parse their contents:
Compression Directive File
Decompression Directive File
Custom Tool Directive File
Finally, the plug-in must ship with a collection of profile files for compression 
 and decompression operations:
Plug-In Profile Files