pattern.html

<!--

	The pattern attribute specifies a regular expression that the <input> element's value is checked against.

Note: The pattern attribute works with the following input types: text, date, search, url, tel, email, and password.

-->










<form> <label for="username">Username <i>(letters and numbers only, no punctuation or special characters)</i></label><br> <input name="username" id="username" pattern="[A-Za-z0-9]+"> </form>