SAP HEADER LINE GLOSRY documentation, setup help and example usage

ARTICLE

header line
Obsolete work area of an internal table , that has the type of the line type and the same name as the internal table. If an internal table with a header line is used in an operand position , the header line is usually addressed. To enforce access to the
table body , square brackets [] can be entered after the table name.
ABAP_MORE_INFO