Documentation 9.8. Data Type Formatting Functions: missing behaviour on invalid input at to_date()

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/12/functions-formatting.html
Description:

For the formatting functions, which convert between a string and a type like
date, timestamp or number, there should be a description about the behaviour
of i.e. to_date(input, mask) in case of invalid, not convertable input.

I expected a return value of NULL and got a execution error.