This is a very small thing, but it came up today for me, so I thought I'd mention it. (Org 9.4.2, for the record.)
I've just started playing with the iCalendar export because eventually I want to keep everything in Org, to then get transformed and pushed to my CalDAV server, which then gets pushed to my phone. So after reading the docs[1][2] I created a minimal org file, which as it happens only had a single time for the single event in it. I tried to export via C-c C-e c f, and immediately got an error that org-agenda-default-appointment-duration wasn't set (which was perfectly true, I hadn't set it and it defaults to nil). So after looking at that variable's documentation, just to make sure it was well-named and didn't do something strange, I set it and went on about my merry way. As I say, a very small thing. I mention it only because it was slightly irritating that after actually taking the time to read the documentation, I still had to troubleshoot (if you want to call it that) briefly. All of which leads up to: my suggestion is that either that org-agenda-default-appointment-duration have an actual default value, or else that [2] should mention that one might want to set it. [1] https://orgmode.org/manual/Timestamps.html#Timestamps [2] https://orgmode.org/manual/iCalendar-Export.html
