To not overwrite potential changes the member makes to the prefilled values, filling of these inputs will only be done once, immediately after they are rendered, or after a member logs in. If a member logs out, and another member logs in, the values will not be updated!
The available data types can be found
Examples
Text inputs (input type="text", type="email", type="hidden", textarea)
<div>
First Name:
<input
type="text"
data-ms-member-info="firstName"
/>
Last Name:
<textarea
data-ms-member-info="lastName"
>
</textarea>
</div>
Text and number type fields will be rendered normally
Select (radio) type field value will be used to fill out the input
Multiple select field selected values will be comma and space separated ("apple, pear")
Checkbox type fields will be rendered as "Yes" or "No", translated per the selected language