I have a php page. The code is:
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<meta name="viewport" content="width=device-width">
<?php include("some_file.php"); ?>
<title>Calculadora dos Custos do Automóvel</title>
As others have said BOMs are a problem when including PHP files, even if those files do not echo anything
At the time this article was written, if you include some external file in a page using PHP and that file starts with a BOM, it may create blank lines.
This is because the BOM is not stripped before inclusion into the page, and acts like a character occupying a line of text.
You should ensure that the included files do not start with a BOM.
You can online detect BOMs within the content of your HTML page using the W3C Internationalization Checker