this is a result of some help I received a few days ago in the #emacs 
irc chat room on freenode.

I was wondering why we were adding a semicolon in front of names, before 
creating symbols, and I understand this is because such symbols work as 
keys.  next, I could not find how we were taking advantage of this in 
the code, asked further, looked for references and examples, and 
discovered how to use `cl-destructuring-bind' to define something 
looking and behaving like a `let' block, based on the content of a plist.

hope this helps.

I have signed my FSF papers, and received confirmation of reception.

ciao,

Mario