Hi Preeti,
SO10
With this Tcode you will be able to create a fixed text for use in the long texts of any Object (Notification Order etc)
Case1
After creating one such Fixed long text
Now run IW21, click on long text icon, click on the Include in the menu bar --> Text --> Standard
Now in the resulting pop-up do this.
All the long text created there is imported here.
Now if you create an Order through this Notification the Order will be created with this Long text.
Case2
If you are using a Maintenance Plan to create your Orders then have this text in a similar way to the Longtext of the Maintenance item. All the Orders triggered through this plan will be having this long-text.
Hope this information is useful.
Jogeswara Rao K