I just find out that when you set 'No' in the 'Show in detail view' for  a custom field it is hidden ONLY when it is empty and the information is collaped, which is I think the most misleading name for it I have seen.

Since Pipedrive doesn't offer not editable fields I'm surprised why it is not possible to actually hide a custom field and also if I want to store some additional information about the company or deals that is only needed for APIs, the view of every user will be filled up with unneccessary information, which is very counterproductive in my optinion.

Also if you just keep the functionality of that field, please rename it so the name represents of what it acually does.