This is basically used for kendo ui text-box required validation. The code sample as given below.
<div class="col-sm-8 col-md-6">
<div class="col-sm-8 col-md-6">
@(Html.Kendo().MaskedTextBoxFor(model
=> model.Name)
.Name("Name")
.HtmlAttributes(new
{
required = "required"
})
)
<span data-for='PhoneNumber' class='k-invalid-msg'></span>
</div>