How E1TXTH9 is created in WHSORD ?

Hi,

I have an Idoc WHSORD, type DELVRY03. Do you know how Idoc creates E1TXTH8 and E1TXTH9 segments.? In one case (comparing ID ) I want to make a copy E1TXTH8 in E1TXTH9. Are there any table where is information which type text will be in E1TXTH9 segment ?