BUG #18857: Abnormal string comparison results

The following bug has been logged on the website:

Bug reference: 18857
Logged by: dlyixue Xu
Email address: 2322370369(at)qq(dot)com
PostgreSQL version: 17.3
Operating system: Ubuntu 22.04
Description:

When I use a conditional query, I find that it returns results that are not
as expected. After checking, I found that there is a problem with string
comparison here.
As shown in the example below, on the ASCII table ‘?’ is larger than ‘&’. I
don't think ‘t’ should be returned here. In the MySQL database it does
return 0.
Is there some special consideration here?

postgres=# SELECT ('?' <= '&*CcCV5');
?column?
----------
t
(1 row)