It specifically refers to this shorthand ?:
that works like this:
$value = $thing_that_could_be_truthy ?: 'fallback value';
# same as
$value = $thing_that_could_be_truthy ? $thing_that_could_be_truthy : 'fallback value';
The condition is also the value if it is truthy
Sorry, I wasn’t saying it wasn’t, I just found it funny, I do trust you know what you’re talking about, had no reason to doubt you