Custom action profiles .mta

[ohrenkino]

Use the functions to add an action instead of editing the mta file directly.
see this description of the How Tos on how to create a new action:

Actions and batch-operations

How to create a new action? First, create a new action group via Actions > [Actions] Actions or Alt + 6. Then, click on the button [New] New and give your action group an expressive name, e.g., "All tag fields Upper Case". This action group can be applied to the selected files after you have added one or more actions to it. Now, you can create a new action in your action group via the button [New] New and choose the desired action type from the list. At the moment the following action types …

If you want to set a certain value in a field, use an action of the type "Format value".
Select the field,
enter the value,
save the action.