[unboggling]

Is series_sort a field that is usable by a calibre user?

I noticed series_sort is listed as a field in Preferences -> Look and Feel -> Book Details. But ticking the checkbox for series_sort in Look and Feel -> Book Details to display it in the Book Details pane did nothing apparent. No series_sort field showed up there.

Also series_sort is listed as a field in Edit Metadata in Bulk -> Search and replace -> Regular Expression mode in both the Search field and the Destination field menus. When I select it as Search field there, no values show up in the test area below.

There is a template function series_sort() which works fine as {:'series_sort()'} for composite column. I assume it applies the function to the value from the field series, according to the tweak Control formatting of title and series when used in templates. When I set that as save_template_title_series_sorting = 'library order' the composite column shows the series sort with ", The" or ", A" at the end, working as expected.

(Just for kicks I also tried the other tweak Control sorting of title and series in the library display set to title_series_sorting = 'library_order'. That worked as expected.)

I think I understand the template function series_sort().

But I don't understand why if series_sort is also a field in itself, it doesn't act like a field. There seems to be provision for a series sort column in the backend. Is this another one of those legacy things?