# Masks

The MaskedTextBox supports a set of built-in masks.

The supported mask rules are:

* `0`—Requires a digit (0-9).
* `9`—Requires a digit (0-9) or a space.
* `#`—Requires a digit (0-9), space, plus (+), or minus (-) sign.
* `L`—Requires a letter (a-Z).
* `?`—Requires a letter (a-Z) or a space.
* `A`—Requires an alphanumeric (0-9, a-Z).
* `a`—Requires an alphanumeric (0-9, a-Z) or a space.
* `&`—Requires a character (excluding space).
* `C`—Requires a character or a space.

You can also define custom rules by using the [`rules`](https://www.telerik.com/kendo-vue-ui-develop/components/inputs/api/maskedtextboxprops#rules) property.

Apart from the built-in and custom rules, you can also use static symbols in the mask pattern that are also known as literals. In the masked value, a literal is always rendered on the same position as the position where it is defined in the `mask` property.

> To escape a mask rule, use the slash (`\`) character. An escaped rule turns into a literal.

The following example demonstrates how to use the digit-requiring mask (`0`) and the literal (`-`) of the MaskedTextBox.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/inputs/maskedtextbox/masks/basic/source.txt)

The following example demonstrates how to extend the available mask rules.

[Demo Source](https://demos.telerik.com/kendo-vue-ui/inputs/maskedtextbox/masks/extend/source.txt)

## Suggested Links

* [API Reference of the MaskedTextBox](https://www.telerik.com/kendo-vue-ui-develop/components/inputs/api/maskedtextboxprops)