Довідка LibreOffice 24.8
Toggles the Design mode on or off. This function is used to switch quickly between Design and User mode. Activate to edit the form controls, deactivate to use the form controls.
Please note the Open in Design Mode function. If Open in Design Mode is activated, the document is always opened in Design mode, regardless of the state in which it is saved.
If your form is linked to a database and you turn off the Design mode, the Form Bar is displayed at the lower margin of the document window. You can edit the link to the database in the Form Properties.