Question

I was looking into multi-byte characters and how they are used but how many different identifiers/pasterns are used for different multi-bytes.

e.g: &nbps;,&#nbsp;,U+0026,%20

how many different identifiers such as &,&#,u+ ,% etc are there ?

Im trying to look for inputs if they have words which are more than 255 characters long then its probably a multi-byte (hack attempt) and then I can check if word can be split has the multi-byte identifier then stop the hack attempt.

Answer 1

% format – a url-encoded value for embedding into URLS, e.g. %20 is a space (ascii 20)
  – named character entity, a non-breaking space in this case
U+0026 – a unicode character in hex notation, an & in this case
&#...; – a numbered character entity in decimal (base10) & = &
&#x...; – a numbered character entity in hex (base 16): & = &