How can I add a title to a field in the checkout page? I am wondering if there is a simple way (dropdown option or checkbox) to add a title to a field in the Drupal Commerce checkout page.  Specifically, I want the second field for Street Address to have the label: Address line 2.


  


I was unable to find this field in Admin > Structure > View that allows the option to "Manage Display" or "Manage Form Display" and make a label for a field "Hidden" or otherwise.

I also looked in the Commerce sections to no avail.  

Next step is to find out if there is a Billing Information > "Manage Form Display menu somewhere.

Not in 
Home > Administration > Configuration > People > Profiles > Profile types  > Edit Customer > Manage fields 
either.
Not possible in User Interface (via link or menu or whatever). But if you use the following code in a module, you can add a title to your form element:

&lt;?php
function CUSTOM_form_alter($form, $form_state, $form_id) {
  // You should probably check for a form_id in here, as this runs on every form.
  // Below you will need to find the part of the $form array that has the billing address.
  $form['[see note above]']['widget'][0]['address']['address_line2']['#title'] = t('Address 2');
}