Begin of Secondary Information BSC (17)/End of Secondary Information ESC (18) 
Definition
Secondary information begins with the BSC operator and ends with the ESC operator.
Between the BSC operator and the ESC operator, there is a number of table entries and the actual table containing the secondary information.

The begin secondary information operator indicates that secondary information follows.
No. |
Operand |
Length |
Type |
Example |
1 |
Number of table entries |
6 |
Numeric |
000016 |
2 |
Table of secondary information |
from ABAP Dictionary |
PPU12_SEC |
The end secondary information operator, which has no operands, closes the begin secondary information operator.