License block / Original Code is...

A friend is helping me with a code snippet ( his md5 implementation ) 
which I use in a Flickr extension in Minimo. I will attach the 
trilicense block to this script, and I have a doubt about the formal 
aspect / defition of Original code.

I see source from mozilla which Original code sometimes refer to an 
entiry, to a person, and sometimes to a code title. So I wonder feedback 
  on what is the best definition of it and/or if you have an URL I can 
read more..

/\/\arcio