Undocumented cite grouping rule?

I am rendering

(Aalto 2015a–e; Bartleby 2010)

for the name_CiteGroupDelimiterWithYearSuffixCollapse2 test but it wants

(Aalto 2015a,b; Bartleby 2010; Aalto 2015c–e)

They differ because I’ve applied cite grouping but the test does not.

Helpfully, the test explains itself:

Cite grouping is applied only if the citations are sorted in some way, otherwise they should be rendered in entry order.

However, that seems to differ from the documentation which says only that

Cite grouping can be activated by setting the cite-group-delimiter attribute or the collapse attributes on cs:citation

It mentions no need for a <citation><sort/></citation> element and I can’t think of a reason why that should be required.

It would be an easy change to do what the test wants but I’m curious about the reason and why it isn’t documented.

Well, I think it’s a two step process. First question is whether to sort or not, second question is how to group cites that happen to be next to each other. While sorting is usual in some disciplines’ it would be very weird to do that in others. The order of cites may be semantically significant.

Thank you. Fair enough. I may offer a PR to make that more clear in the documentation. Luckily, it was a one line fix on my end.