While filling the form elements on mobile screens labels and instructions help the users identify the purpose of the form. On a mobile it is not sufficient. If the user need to type in an address field, the content required to be typed in with address line 1, address line 2, selecting state or country from the drop down etc. In the process they need to change the keyboard from alphabetic to numeric and symbols. Imagine how tough if the same has to be done while using voiceover or talkback?
By accommodating with certain input methodologies this processes can be minimized.
How to identify input purpose
Below are some suggestions to ensure that the typing experience with various abilities, assistive technologies is smooth and comfortable.
Type: As defined in android input type and IOS keyboard type, depending on the expected user input type, ensure that the appropriate keyboard for the field is displayed. For instance, if the user need to fill in the phone number, the numeric keyboard is appropriate where as to provide an email address, the keyboard that is optimized for email address (with . and @) are are appropriate.
Autocomplete: If technology supports, wherever possible provide autocomplete behavior for input elements.
Autofill: If technology supports provide a mechanism that stores the user data on the device and autofills the same depending on the input element. This will reduce large amount of effort the user has to put in filling the elements on the screen.
WCAG Success Criteria
1.3.5 Identify input purpose (Level AA) WCAG 2.1