Why are there "<IRQ>" and "</IRQ>" in the call trace section? What does them imply?

[CVS]

While i am not sure why this notation was chosen,
at least one precedent would be HTML
where an element is defined by
a starting tag named within angle-brackets
and the end of the element is defined by
a corresponding tag with the the same name prefixed with a "/"

https://en.wikipedia.org/wiki/HTML_element#Syntax

regards
CVS