SZS is only a file extension, not a file format. It is short for Seven Zip Stream (or something similar) and indicates that a file is compressed using Yaz0, Nintendo's favorite compression that has been used since the Nintendo 64. No files should be known as SZS files. They should be known as the file content's file format. SZS files should be decompressed and then analyzed for better knowledge of the actual file format and its contents.