A friend of mine (a LH pilot), after speaking to a purser, told me the following:
Every flight (at least intercont) receives a PIL (Passenger Information List), containing the status passengers. There are: HON, SEN+, SEN, FTL+, FTL.
They use this list for example to decide whom to upgrade to F if necessary in last minute. The purser might also decide based on this list how much effort to put on the reseating of a passenger with broken IFE, or just to apologize and hand out a miles voucher for compensation.
A SEN+ is close to becoming HON, a FTL+ is close to becoming SEN.
Thats what my friend told me, I dont know if its true and I have never been on a LH intercont flight in the last 8 years or so.
So its up to you to decide if this could be the truth, according to your experiences on bord.
Cheers
Hamburger