 tags.  This hash is cleared at the start of processing for each directory.
    Not used during when writing.</td></tr>

<tr><td>LOW_PRIORITY_DIR</td><td>Lookup based on directory name for directories where
    undefined Priority tags get set to Priority 0 (eg. PreviewIFD in all images,
    and IFD1 in JPEG images).  This is equivalent to setting PRIORITY to 0 for
    the tag table only for a specific directory name.</td></tr>

<tr><td>Make</td><td>Camera make set during reading and writing</td></tr>

<tr><