How to add an account field that is hidden

How create an account field (that is applicable for all accounts) that can only be accessed and change by administrator at the admin page only

For example in the table : fl_account
Create another field : extra_field

extra_field (drop down option)
- Trusted Seller
- Normal Seller

Shall be displayed in page "listing_details.tpl"

{if $listing_data.extra_field}<li>{$listing_data.extra _field}</li>{/if}

Hello,

Unfortunately we don't have this option. You can make it manually or submit a ticket to our technical support and we will be able to make it as customization.