FPL9's Line Item Description (Part 2)

CALL FUNCTION 'ISU_GET_TRANSACTION_TEXT'
EXPORTING
x_applk = p_postab-applk
x_spras = p_langu
x_bukrs = p_postab-bukrs
x_sparte = p_postab-spart
x_hvorg = p_postab-hvorg
x_tvorg = p_postab-tvorg
IMPORTING
h_votxt = p_postab-votxt.

This is how SAP get the text and display on the basic list in t-code FPL9