When the linker combines global symbols the visibility of the symbol is set with the strictest visibility of the symbols being combined. Therefore, a symbol reference with STV_HIDDEN visibility combined with a definition with STV_DEFAULT visibility results in a definition with STV_HIDDEN visibility.

This option enables the linker to use the visibility of the definition in preference to the visibility a reference when combining symbols. For example, a symbol reference with STV_HIDDEN visibility combined with a definition with STV_DEFAULT visibility results in a definition with STV_DEFAULT visibility.

This can be useful when you want a reference to not match a Shared Library, but you want to export the definition.