In order to do this, please follow the steps below:

1) Go to "Advanced Settings > Fields" (for Projetex: "Corporate settings >> Fields" in the Server Administrator utility), add any group of custom fields and then the field itself (for instance, "Client actuality" with the "text line" field type).
2) After saving changes, return to the client profiles page and enter "no" (just an example) into the custom field you just added in the Custom tab of every non-actual client profile.
3) Click the Edit button in the "Local Custom Filter" box and choose "Client actuality" from the parameter list, click on "contains", select "is not equal to" as a condition type and enter "no" as the condition value.

An alternative method is to transfer all inactive clients into the Prospects section of the database.

To do so, just select a client in the Clients>>Main tab, click the "More.." button (right next to the "Delete" button) and select "Move to Prospects".

The client and all associated data will be safely stored in the Prospects section.