You can manipulate interaction fragments with some limitations.
You can move interaction fragments, resize them, and generally manipulate them freely. When you cause the symbol to overlap an object lifeline, it attaches to it automatically, and this attachment is represented by a small bump on the top edge of the symbol where it meets the lifeline. If you drag or resize the symbol away from a lifeline, it detaches automatically.
If you move an object that is attached to an interaction fragment, the symbol resizes itself automatically to remain attached to the object lifeline.
You can manually control whether object lifelines are attached to an interaction fragment that passes over them by clicking the attachment point.
Any message that is entirely enclosed within an interaction fragment will be moved with the fragment up and down the object lifeline to which it is attached. However, if you move the fragment away from either of the lifelines to which it is attached, the message will be detached from the fragment and not moved.
You can move messages freely in and out of interaction fragments. If you move a message so that it is completely contained within a fragment, it will be attached to that fragment. If you move a message so either of its ends is outside the fragment, then it is detached from the fragment.
When a fragment is split into two or more regions, you can move messages freely between regions. However, you cannot move the dividing line between two regions over a message. You can resize a region by moving the dividing line below it. Such resizing will affect the total size of the fragment. To resize the last region, at the bottom of the fragment, you must select and move the bottom edge of the fragment.
If you delete a region, then the space that it occupied and any messages it contained will be merged with the region above.
Note that an interaction fragment cannot be copied as a shortcut in another diagram.