In the tags list , right-click on the top row and click on "More..." to choose the property to modify and add the column to the list
In this example, we want to mask one set of tags by another, to do so we select "Masked by (alarm)"
Now you need to select tags to modify and right-click on it, then choose "Edit property".
Be careful, you must do the right click on the new column, usually it appears at the end of the list, you may have to move the scroll bar to find it (or adjust their width to see them all)
Here we must select a tag in the supervision list (aka the tag list)
Therefore, the masking tag was modified simultaneously on all the selected tags.
N.B: Please note, some properties are not compatible with this procedure
example: call group