[ccp4bb] a question on Average Occupancy-weighted avg temperature factor (Deviation)

[Dialing Pretty]

Dear All,
 
For the RCSB depositation report, it gives the "Average Occupancy-weighted avg 
temperature factor (Deviation)".
 
Will you please tell me what range the "Average Occupancy-weighted avg 
temperature factor (Deviation)" should be and what is the significance of that 
value?
 
I am looking forward to getting your reply.
 
Cheers,
 
Dialing