Very often you want to re-use an existing piece of information. Examples are:

1. One-to-One re-use: you already have a person on one page, and want to use the same person on another page
2. Use in list and again standalone: you already have a person to one page, and now want to add him to a list of people manually
3. Re-use with different layout: you already have a person on one page - showing the face and name, and now you want to show the same person on a google map

This is very easy in 2sxc, as you can always choose to re-use an existing item instead of adding another. 

So you have two options

1. re-use item which are the same item
2. re-use a copy of an item