Numerical value describes start offset and is an optional field.
Numerical value of 20 means that blackbox data is requested starting from 20th latest event.
When # is omitted the latest events are packed to single SMS.
Example:
X1:Y1,X2:Y2,…,Xn:Yn, where:
Xn – HEX value of event ID.
Yn – HEX value of custom data field (optional).