[LisaBarry]

Hi,

I need to be able to check if the Identifier is filled out on a large number of EPUB files. I think Calibre looks like a tool that could possible provide me with this functionality. However, I cannot see this column by default and I'm wondering how I can show or add the column to see the information I need.

From looking in the .opf file code of my EPUBs - the Identifier number I need to check appears to be here:
<dc:identifier id="PrimaryID">360026123592</dc:identifier>
And here:
<dc:identifier id="ISBN">360026123592</dc:identifier>

If I could show either of these numbers in a column that would be great. I tried adding custom columns but I'm likely not doing it correctly (see screenshot).

I would greatly appreciate any help/suggestions on this.

Thanks,
Lisa