What are the potential pitfalls of using ISO-8859-1 encoding for PHP documents on Linux?

Using ISO-8859-1 encoding for PHP documents on Linux can lead to character encoding issues, especially when working with non-ASCII characters. To avoid problems, it is recommended to use UTF-8 encoding for PHP documents, as it supports a wider range of characters and is more universally accepted.

// Set UTF-8 encoding for PHP documents
header('Content-Type: text/html; charset=utf-8');