Which TIFF IFD fields are required in OME-TIFF?
The only requirement is that the ImageDescription directory entry must be present in the first IFD, and populated with a valid OME-XML metadata block.
Otherwise, OME-TIFF files do not need any IFD fields beyond what would be required for a regular TIFF. Please see the TIFF specification for a list of IFD fields required for regular TIFFs.
