What best practices should PHP developers follow when designing URL structures for their websites to improve search engine friendliness?

When designing URL structures for websites, PHP developers should follow best practices such as using descriptive keywords, separating words with hyphens, keeping URLs short and readable, and avoiding unnecessary parameters or query strings. This can improve search engine friendliness and make it easier for search engines to crawl and index the website.

// Example of a search engine friendly URL structure in PHP
// Using descriptive keywords and hyphens for readability

// Original URL: example.com/index.php?page=about-us
// Improved URL: example.com/about-us

// Rewrite rule in .htaccess file
RewriteEngine On
RewriteRule ^about-us$ index.php?page=about-us [L]