Note that the label also displays “(required)”, to inform users that don’t use assistive technology or use older web browsers that do not support the HTML5 attribute informs assistive technologies about required controls so that they are appropriately announced to the users (as opposed to validating the input).
Most current web browsers automatically set its value to .
Tie budget period sets to budget closing rules and Commitment Control ledger groups.
Specify which ledger amounts apply toward calculating the remaining budget balance.
This is useful for specific types of data patterns such as telephone numbers, postal codes, and serial numbers.
In the example below, the element specifies a particular format that matches car license plate (registration) numbers in Germany.
Input errors, such as an incorrect email address, will be indicated using the web browser dialogs as in the previous example.
attribute allows the use of regular expressions to specify custom formats for the input.
Custom validation needs to notify users in an accessible way as described in the User Notifications part of this tutorial.
HTML5 input types are displayed as simple input fields in older web browsers that do not support these HTML5 features.
The example below shows these HTML5 input types in action.
The required pattern consists of one to three letters (for the city where the car is registered), followed by a space, two to four random letters, another space, then one to four random numbers.
Validation should aim to be as accommodating as possible of different forms of input for particular data types.