Unrequired property keeps getting data-val-required attribute

This is the model with it's validation: ``` [MetadataType(typeof(TagValidation))] public partial class Tag { } public class TagValidation { [Editable(false)] [HiddenInput(DisplayValue = false)] public int TagId { get; set; } [Required] [StringLength(20)] [DataType(DataType.Text)] public string Name { get; set; } //... } ``` Here is the view: ``` <h2>Create</h2> <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script> @using (Html.BeginForm()) { @Html.ValidationSummary(true) <fieldset> <legend>Tag</legend> <div>@Html.EditorForModel()</div> <p> <input type="submit" value="Create" /> </p> </fieldset> } <div> @Html.ActionLink("Back to List", "Index") </div> ``` And here is what get's renderd: ``` <form action="/Tag/Create" method="post"> <fieldset> <legend>Tag</legend> <div><input data-val="true" data-val-number="The field TagId must be a number." data-val-required="The TagId field is required." id="TagId" name="TagId" type="hidden" value="" /> <div class="editor-label"><label for="Name">Name</label></div> <div class="editor-field"><input class="text-box single-line" data-val="true" data-val-length="The field Name must be a string with a maximum length of 20." data-val-length-max="20" data-val-required="The Name field is required." id="Name" name="Name" type="text" value="" /> <span class="field-validation-valid" data-valmsg-for="Name" data-valmsg-replace="true"></span></div> ... </fieldset> </form> ``` The problem is that TagId validation gets generated althoug thare is no Required attribute set on TagId property. Because of that I can't even pass the client-side validation in order to create new Tag in db. What am I missing?