This part of ISO 2566 specifies a method of converting room temperature percentage elongations after fracture obtained on various proportional and non-proportional gauge lengths to other gauge lengths.
DS/EN ISO 2566-2:2000 history
0000 DS/EN 300175-7 V1.9.1:2005
2000DS/EN ISO 2566-2:2000 Steel - Conversion of elongation values - Part 2: Austenitic steels