220: Tag combination already used to tag an item

While you can use the same tag as often as you want in a single-tagged list, multiple-tagged lists require that the combination of tags is only used once. In your case a tag combination is used twice though.

Details for lists of items with a varying number of tags

In tagged lists which contain items with a varying numbers of tags, an item’s full tag combination may not occur again as the initial part of a longer tag combination either. For example, the following list is invalid, because the full tag combination <A><B> from the first line reappears as initial part of the tag combination <A><B><C> in the second line.

<A><B> X
<A><B><C> Y

In contrast, the next list is valid. The full tag combination <E><F> does not reappear later. <E><G> occurs twice as initial part of different tag combinations in the second and third line, but <E><G> is not a full tag combination of any item, so this is okay.

<E><F> X
<E><G><H> Y
<E><G><I> Z


Make sure that every item in a tagged list has a unique tag combination. Order does matter, so <France><Belgium> is different from <Belgium><France> and both can be used in the same list. This could be a list of results from football matches where the home team is named first for example. So <France><Belgium> and <Belgium><France> refer to different matches, one in France and the other one in Belgium.