WPF, DataGridRowHeader, binding to collection

Question

Hello! I have a simple DataGrid. I want to make that every DataGridRowHeader has it own Content. I specified RowHeaderStyle like this:

<DataGrid.RowHeaderStyle>
   <Style TargetType="DataGridRowHeader">
      <Setter Property="Content" Value="{Binding Source={StaticResource RowHData}, Path=Parameters}"/>
   </Style>
</DataGrid.RowHeaderStyle>

But I see only "(Collection)" word in every header. What's wrong ? BTW: Parameters is a List of string