Ok So I've managed to add a custom attribute to my customers currently only view-able on the admin panel side. Its listing out all the options from another module into the multi selects options as well as the default options at the top of multi select.
Now after I made this I decided that it wasn't quite as user friendly as I would like, so I'm wondering about changing this into a checkbox.
I made an update and changed the attribute as follows:
$installer->addAttribute("customer", "brands", array(
"type" => "text",
"backend" => "",
"label" => "Brands",
"input" => "checkbox",
"source" => "registration/eav_entity_attribute_source_customeroptions13632635690",
"visible" => true,
"required" => false,
"default" => "",
"frontend" => "",
"unique" => false,
"note" => ""
));
This however did not work, So I was wondering if check-box is actually a option for making magento attributes (for customers specifically).
If checkboxes aren't an option, would it be possible to customize the front end to display a check-box list instead of the multi select or would this create problems?