This mimetype is deprecated. You should still support it, but avoid using it to assign new mimetypes.
Instead, please use audio/flac
FLAC stands for Free Lossless Audio Codec, an audio format similar to MP3, but lossless, meaning that audio is compressed in FLAC without any loss in quality.
It can encode audio with a PCM bit resolution up to 32 bits per sample and sampling rates up to 640 kHz. FLAC-encoded audio is usually found either in a native container (which has the extension .flac), or in an Ogg container (when it's known as OggFLAC).
File types
.flac