1. Spurious data held in a database through error, incompetence, poor design, poor maintenance, age, misplaced user priorities, but usually due to a subtle confluence of all of these factors.
2. Data that will never, ever be used and is recorded merely because it can be, or must be due to regulation.
3. The lowest qualitative measure in the epistemological hierarchy of wisdom, knowledge, information, data, gumpf.
Wikipeadia contains a lot of gumpf.
I used to read my horoscope in the paper but now I realise they're just gumpf.
Many government computer systems are regulated to store only gumpf.