As you know Sage CRM gives ability to add fields against any entity which can be added on screens to make user interface more interactive. However there are fields which are available by default within the CRM as System fields which don’t get displayed in selection list while we adding them to screens. A sample screenshot of CampaignDetailBox is added below for reference
New Stuff:Tracking your custom fields in SageCRM

Now, if we want to view this field in the selection list to make some changes such as alienation, position, width, etc… So this can be easily done by executing an update query on CRM database. Once query is executed you need to do a Metadata Refresh and you will be able to see this field. Refer below screenshot for your reference.
update custom_edits set colp_system=null where ColP_ColName=’camp_status’

Also Read:
1) Adding new fields on Web Order Item Entry screen
2) Adding new fields on Web Order Entry screen
3) Lead to Opportunity Fields Mapping
4) Display Background Color on Required Fields in Sage CRM v7.2
5) Hide fields and extra spaces in Sage CRM