There is no description what "referenceType" in ItemReferenceBox should be.

[ledyba-z]

according to libavif, referenceType in ItemReferenceBox should be auxl, but there is no information about it in the document.

https://github.com/AOMediaCodec/libavif/blob/e8f56167c9500dc483c17efb495b48b7c3e22cba/src/read.c#L1288

[ledyba-z]

Sorry, it is already written in MIAF(ISO/IEC 23000-22), page 19.

7.4.2 Track reference types
A MIAF reader shall process the following track reference types:
— thumbnail sequence, 'thmb' (as documented in ISO/IEC 23008-12);
— alpha and depth auxiliary sequences, 'auxl' (as documented in ISO/IEC 23008-12);