Filters are an effective way to prevent/limit users from entering incorrect data, before the real validation process is performed.
There are 15 built-in filters and we can easily define our own too (see sample).
Multiple filters can be attached to the same field by using a comma separated list:
<input type="text" name="noquotes" tmt:filters="noquotes,nodoublequotes" />
Please note filters are attached to the fields as soon as the page loads. They don't work on form fields that are added at run-time. In order to enable filters, the tmt:validate attribute of the <form> tag must be set to true