sorry, I forgot to add that the bitrate doesn't tell all.
Other factors like the audio layer & fps & such are also important.
But once you think you have one type, easiest way to check if they are compliant to that standard, is dump it into Nero & if it doesn't come up with an error, than you are good to go. If pops up saying something else, then you have the other type (VCD/SVCD vise versa) or the file doesn't meet the standards to those file types.
Good luck rag-man =) (old jazz term *but am sure you knew already)