public class RegisterModel
    {
        [Required(ErrorMessage = "*")]
        [Display(Name = "Naam")]
        public string UserName { get; set; }

        [Required(ErrorMessage = "*")]
        [Display(Name = "E-mailadres")]
        public string Email { get; set; }

        [Required(ErrorMessage = "*")]
        [StringLength(100, ErrorMessage = "Het {0} moet op zijn minst {2} tekens lang zijn.", MinimumLength = 6)]
        [DataType(DataType.Password)]
        [Display(Name = "wachtwoord")]
        public string Password { get; set; }

        [DataType(DataType.Password)]
        [Display(Name = "Bevestig wachtwoord")]
        [Compare("Password", ErrorMessage = "De twee wachtwoorden komen niet overeen.")]
        public string ConfirmPassword { get; set; }
    }

<fieldset>
    <legend>Register new user</legend>
    <ol>
        <li>
            @Html.TextBoxFor(m => m.UserName, new { @class = "form-control", @placeholder = "Volledige naam"})
        </li>
        <li>
            @Html.TextBoxFor(m => m.Email, new { @class = "form-control", @placeholder = "E-mail "})
        </li>
        <li>
            @Html.PasswordFor(m => m.Password, new { @class = "form-control", @placeholder = "Wachtwoord" })
        </li>
        <li>
            @Html.PasswordFor(m => m.ConfirmPassword, new { @class = "form-control", @placeholder = "Bevestig wachtwoord"})
        </li>

    </ol>
    <button type="submit">Register</button>
</fieldset>

<li>
    @Html.TextBoxFor(m => m.UserName, new { @class = "form-control",
                                            @placeholder = "Volledige naam",
                                            @Autocomplete= "off"})
</li>

using System.Web.Mvc;

namespace MyNamespace
{
    public static MvcHtmlString DisableAutoComplete(this HtmlHelper htmlHelper)
        {
            var UserName = new TagBuilder("input");
            UserName.MergeAttribute("type", "text");
            UserName.MergeAttribute("style", "display:none");
            var Password = new TagBuilder("input");
            Password.MergeAttribute("type", "password");
            Password.MergeAttribute("style", "display:none");
            return MvcHtmlString.Create(UserName.ToString(TagRenderMode.SelfClosing)+Password.ToString(TagRenderMode.SelfClosing));
        }
}

@using (Html.BeginForm())
{
@Html.AntiForgeryToken()
@Html.DisableAutoComplete()
.
.
.