Select Menu > Document properties.
Learn how to add, edit and delete custom document properties to store specific metadata in your PDF files using Adobe Acrobat.
Windows
In the dialog box that opens, select the Custom tab.
To add a property, type the Name and Value, and then select Add.
To change the properties, select the property you want to edit, modify the name and value as desired, and then select OK.
To delete the property, select it and then select Delete.
Select OK.
macOS
Select File > Document properties.
In the dialog box that opens, select the Custom tab.
To add a property, type the Name and Value, and then select Add.
To change the properties, select the property you want to edit, modify the name and value as desired, and then select OK.
To delete the property, select it and then select Delete.
Select OK.