As far as I understand, if the [] is absent, any data that might go into the trailing S would go into the leading S. If it is present and OC contains a comma, then any data that might go into the trailing S would go into the OC. Otherwise, it would go into the last S of the repeat expression or into the S after the first item -- at any rate, no data can wind up in that position.
It does no harm, and it might be too late to change the ABNF -- but it should be documented somewhere, and this issue is as good as any place for it. Feel free to just close it if it's not going to be changed.
There is a trailing
Sin theseqABNF:As far as I understand, if the
[]is absent, any data that might go into the trailing S would go into the leading S. If it is present andOCcontains a comma, then any data that might go into the trailing S would go into the OC. Otherwise, it would go into the lastSof the repeat expression or into theSafter the first item -- at any rate, no data can wind up in that position.It does no harm, and it might be too late to change the ABNF -- but it should be documented somewhere, and this issue is as good as any place for it. Feel free to just close it if it's not going to be changed.