If you want to make your songs available to the public, e.g. for downloading on the Internet, there is a special file format for this. A Reason published song (Windows file extension ".rps") is much like a self-contained song, but has the following restrictions:
The user cannot save any changes to the song.
Copy, Cut and Paste is disabled.
It is not possible to use the function Export Song/Loop as Audio File.
In a word, published songs are "locked". They are meant for playback only - no elements can be added, removed or extracted. Furthermore, a published song contains information about which ReFills are required (if any).
To create a published song, pull down the File menu and select Publish Song. Specify a name and location for the published song in the file dialog that appears, and click Save.
Note that you don't have to make self-contained settings - all files (except ReFill components) are automatically included.