When creating or editing an asset, under the Info tab, there are 3 "custom fields". The default names are "Custom 1", "Custom 2", "Custom 3". These field names can be edited in an organisation.

You will see these fields under create/edit asset, and in some reports. 

These fields can be edited by the organisation manager user:

  1. Go to Admin -> Organisations.
  2. Click on the org you wish to edit.
  3. Go to the Customisation tab.
  4. Edit the field names.
  5. Click Save.

These custom fields are shown in the Edit Asset dialog here: