In the context of the Italian file-sharing communities (like DDLVillage or TNT Village ), a "useful post" usually meant:
Many of these releases included both the original English audio and the Italian dub. Lost_2x04_Tutti_Odiano_Hugo_ITA_DVDRip_XviD-tri...
If you are looking for information about this specific episode or why it was considered a "useful post" in a forum context, In the context of the Italian file-sharing communities