Not knowing your level of familiarity with MS Project views and how they are constructed, this sounds like something that frustrated me when I first started using the tool. Project views are comprised of several components, one of which is the Table. The table component of the view contains all the columns displayed on the left side of a view. A Table can be shared across many views. For example, View1 thru View5 may use the Entry table. If you open View3 and decide to add the Flag1 column to View3, you are in essence modifying the Entry table used across Views 1 thru 5. Now, when you open View1, View2, View4, or View5, you also see the Flag1 column added. Any changes to the shared Table such as reordering columns, sizing columns, changing column headings and so on will now appear in any View that uses that Table.