Hi Luciano,
If you see this when converting GDS to OASIS in DESIGNrev, I think it's because the OASIS format does not support all the same text string characters as GDS. In this case, it looks like it's converting a line feed (not supported) to a space. Not sure that you need to do anything here. This technote might be related: https://supportnet.mentor.com/portal?do=reference.technote&id=MG249336
regards,
matt