Hi Torstein,
This is just a delimiter in the collapsed "module event combination" column to provide a different human readable separation between the event type and event count.
For example, a value like "ir^1|afe^1|multi_exon_spanning^2", means "one intron retention event, one alternative first exon event, and two multi-exon-spanning events" in that module.
Let me know if it makes sense.
Thanks,
-San