Thanks for the tip kafiend, it's obviously " - ", i must have broken it the last time it was updated.
The note should read something like:
... always be separated using " - ", never with "&", "-" or "+".
A little explanation, before this TNC version, we accepted both " - " and " + " to separate groups, it was used to distinguish between a cooperative work by two groups and independent works (one group cracked it after other).
Since this usage was never followed apart from Amiga dats and some TKaos works we deprecated it. It added unneeded complexity and was far from perfect, after all, when a set is cracked by two groups it is almost always cooperative, if other group works on a cracked set already, it may be to add trainers or to fix a non working crack.
Because of all that we simplified it and not we use only " - ".
The note was added because, probably long ago, some renamers never followed the rule and trimmed the white spaces, specially on C64 sets as DuncanTwain may have found by now, there are a lot of sets using "TBT-BLF", "FDF+ASD", "Expendables & Razor" and so on. This is wrong, breaks the convention and makes my life much harder trying to parse info automatically. Even if these strings represent 2 groups, according to the rules they are seen as single one and should be done properly.