Field help (PPSSEQ) 

Proposal sequence
The proposal sequence is used to assign the free locations on stock receipt in an order other than the alphanumeric format of the location, specifically where the storage method is dynamic.
For instance: If the filling criterion gives the priority to storage in the order of the lowest level in the warehouse, the priority sequence can be AAAEBFF for a location format AAABEFF.
The locations are then proposed in the following order: 1 warehouse AAA 2 level E 3 zone B 4 rack FF