When working with an Ots file at the item/chunk level, as opposed to editing the actual data within chunks, the following can easily be achieved:
You can alter the order that items appear in an Ots file, simply by dragging a given item to a new position. You can delete an item, by right-clicking and choosing delete, or by pressing the Del key
You can also drag and drop actual chunk references around. When doing this, one of three things can be achieved: You actually move the chunk to a new location (item). You copy the chunk to a new location -- the old chunk still exists. Or thirdly, you create a second reference (link) to the existing chunk from the new location. Depending on whether you hold down the Ctrl key, the Ctrl+Shift key combination, or nothing, will determine which operation takes place. The mouse pointer alters to reflect which operation will occur.
It's helpful to realize that the chunks that appear in the chunk map tree-view, are not strictly-speaking, chunks at all, but rather are purely references to chunks. Normally there is a one-to-one relationship of references to chunks, which is why it is easier to think of the references as being actual chunks. However this is not strictly true. The Ots file format supports multiple references to any given chunk. This is why you can create a second link to an already existing chunk. When you delete a chunk, you are really only deleting the reference to it. However, once the last reference to a given chunk has been deleted, the chunk itself is also deleted.
If you find the concept of chunks vs. references, a little confusing, then don't worry. You don't normally need to worry about it. It is another architectural design feature that makes Ots files extremely powerful, and means that there is virtually never a reason to have the same data stored twice (redundant information).
How to add a track to an Ots file
How to remove a track from an Ots file
Editing your Ots files