When to use mb_* and when not
Let's say I have an `UTF-8` text like this:

    âàêíóôõ <br> âàêíóôõ <br> âàêíóôõ

I want to replace `<br>` with `<br />`. Do I need to use `mb_str_replace` or I can use `str_replace` ? 

Consindering `<` `b` `r` `/` `>` are all single byte char?
When to use mb_* and when not
===

Let's say I have an `UTF-8` text like this:

    âàêíóôõ <br> âàêíóôõ <br> âàêíóôõ

I want to replace `<br>` with `<br />`. Do I need to use `mb_str_replace` or I can use `str_replace` ? 

Consindering `<` `b` `r` `/` `>` are all single byte char?