Default installations of Apache usually alias /icons to Apache’s icons directory which cannot be overridden in an .htaccess file. If you do not control the Apache configuration of a server, and for maximum compatibility, it is always best to never have an /icons directory at a website’s root level.

On a Debian, for example, the following is defined at /etc/apache2/mods-available/alias.conf:

Alias /icons/ "/usr/share/apache2/icons/"

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