Hi Albaity,
As you probably know, each random number represents a bit of information. PRBG generates number of functions from ensemble which defined by number of elements “n” in this ensemble.
A seed number is a random variable which can be inserted in this ensemle.
Trailing and leading “0”s are defined numbers at the and the beginning of this ensemle (respectively). In my opinion, such pre-defined structure can be used for error correction or balancing “1”s and “0”s.