For anybody looking for a way to do this from the code behind, you can add the extra list item there by using the `Insert` function and specifying an `Index` of 0, as mentioned in this [SO Question](https://stackoverflow.com/a/81379/1366033).  Just make sure to do so after you've called `DataBind()`



    myDropDownList.DataSource = DataAccess.GetDropDownItems(); // Psuedo Code
    myDropDownList.DataTextField = "Value";
    myDropDownList.DataValueField = "Id";
    myDropDownList.DataBind();
    
    myDropDownList.Items.Insert(0, new ListItem("Please select", ""));

For my ASP.NET page, in the code behind I load various items/options into a DropDownList but I do not set a default by assigning SelectedIndex. I notice for the postback SelectedIndex is set to 0, even if I never set focus to or changed the value in the DropDownList.

If not otherwise specified in the code behind or markup, will a default value of 0 be used for the SelectedIndex in a postback with a DropDownList? If yes, is this part of the HTML standard for selection lists, or is this just the way it is implemented for ASP.NET?