http://www.psdevwiki.com/ps3/NPDRM_Selfs this is for eboot.bin type NPDRM Selfs.
With this type (like DLC or PS3 PSN games), you got the need of loading an RIF (or RAP) to decrypt it.
RIF file having the key to decrypt it, as well as others specific informations tied to your PS3 (act.dat)
(so to resume, from RAP with inside a key, this RAP file got transformed and tied to your PS3-->become a RIF)
So if you got only a RIF without furthers infos, it s no good. If you got a RAP, you can use it to make a RIF
for your PS3 (and use reactPSN for example). Or as this page said, resign the eboot as type 3 to use a generic klicense.

For EDAT: http://www.psdevwiki.com/ps3/EDAT_files
Same but here you got an other key needed, called dev klicense.
This key is inside the eboot (NPDRM self, than you have decrypted before).

Here also, there are License Types. If you resign the edat as free (resigned with a generic key the PS3 has),
you can remove the need of this (RIF which has a unique key per game let s said).

Some content don t have eboot.bin but got edat such themes, PS1 games. They also need this klicense (RIF or RAP)
and dev klicense (but instead of being inside the eboot.bin it s a generic key inside all PS3)

If you want to try by yourself, start with a PS1 game or theme before PS3 games.