Filter certain characters from file name, for nicer (more SEO-friendly) URLs as well as better filesystem compatibility. Can be used for files and folders.

Caution: Does not take care of full filename sanitization in regards to directory traversal etc.,
please use PHP's built-in basename() for this purpose.
The default sanitizer is quite conservative regarding non-ASCII characters,
in order to achieve maximum filesystem compatibility.
In case your filesystem supports a wider character set,
or is case sensitive, you might want to relax these rules
via overriding .
To leave uploaded filenames as they are (being aware of filesystem restrictions),
add the following code to your YAML config:
default_use_transliterator: false
See for a more generic implementation.