The user registration form in Touch 5 has a call to the core_advanced_mobile_customSignupFields() macro that allows you to add custom fields using HTML and UTL.
You can find and edit these macros in the insert.utl file in your site component.
To access this file navigate to Design / Templates. Template files are located in the menu on the left-hand side of the screen. In order to access the site component click on the Components tab.
The site component for your site will be an uncertified component, a green puzzle piece without the letters “TN,” and will begin with core_site.
The insert.utl file is located in the macros folder of your site component. If you do not see an insert.utl file in this folder you need to create one. To create an insert.utl file, click on the macros folder and create a new file. Name the file insert.utl.
Once you are editing your insert.utl file you need to add core_advanced_mobile_customSignupFields() macro and format your registration field to match the existing fields.
Here is an example using the macro to create a custom field:
[% macro core_advanced_mobile_customSignupFields(); <li data-role="fieldcontain"> <label for="first_name">First Name</label> <input type="text" name="first_name" id="first_name" placeholder="First Name"[%if cms.request.param('first_name') %] value="[% cms.request.param('first_name') %]"[% end %] required="required"/> </li> End; %]