icalfilter(1) on Linux
The text f8990c2b1245, as Debian 11 (Bullseye), Debian 10 (Buster) shipped it.
filter an iCalendar file based on class and/or category
Flags it lists
-
--category -
--class -
--not-category -
--not-class -
-C -
-P -
-c -
-p