The following links should all have the query string ?P=5%B02%27.
example.com/query?P=5%B02%27
www.example.com/query?P=5%B02%27
http://www.example.com/query?P=5%EF%BF%BD2%27
http://www.example.com/query?P=5�2'
https://www.example.com/query?P=5%EF%BF%BD2%27
They are fractions of the format m/(2^n), but they only mimic fractions like 2/5.