DCP-o-matic

Hi,

Some DCPs has the ASSEMAP and VOLINDEX without extension,
and others (as DOM) with xml extension.

It Is optional as DCI compliance?

Regards,
Jaume

As far as I know IOP without extension, but SMPTE with extension .xml

yes, without XML extension is created when Interop is wrapping scheme in DCP-o-matic, with extension when SMPTE is selected. Similarly, in Interop mode, subtitles go to subtitle-per-reel folders, and to MXF files in SMPTE mode.