This is an advanced property. It is only useful when dealing with interoperability issues with 3rd party Zip tools and Unicode characters. Unless there is a specific need, the property should be left to its default value.
The Zip format uses the IBM PC character encoding set, commonly referred to as IBM Code Page 437 to write filenames in its headers.
Windows has a registry setting that specifies what OEM code page is to be used for DOS-based programs. The value is located in the value "OEMCP" under registry key "HKLM\SYSTEM\CurrentControlSet\Control\Nls\CodePage".
On English-based Windows installations, the value is code page 437, which matches the Zip specification. Windows installations in other locales might have different values for this setting. For example, a Vietnamese installation might use value 1258.
As a service to applications based in these other locales, Xceed Zip for .NET uses the code page of the local machine to write file names in headers. This allows, for example, a Vietnamese language based application to use its own special characters in zipped filenames.
With the advent of Unicode, relying on the code page for non-ASCII has become deprecated as it was never an optimal solution in the first place. Zip files created on a machine with a particular code page would not extract the filenames correctly on another machine that uses a different code page.
To preserve existing behavior for long-time users of the component, the default value of this property is to enable the use of the local machine's code page.
In practice, the code page has little to no effect because the component's default behavior is also to include Unicode extra headers that encode the file names and comments as Unicode in archives.
There is one scenario where it is necessary to set this property to false. The component has the ability to use any ASCII character as the fallback conversion when it converts a Unicode filename to ASCII for storage in a zip file. To use this feature, the local machine's code page cannot be used as the component then loses control over the string conversion.
In this case, an application will set the property to false, making the component always use code page 437, and set the desired fallback character to use.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2