Main titles that are also series names

[Miss Pageturner]

Dear fellow Librarians
I have a question about titles that are also series titles. German publishers very often design books in such a way that the series name is the main title, and each volume then gets an individual subtitle. The covers are also designed according to this scheme. The main title, which is also the name of the series, is printed in large letters on the cover, and the subtitle of the volume is printed in small letters.

My question is how the titles should be indicated. German publishers and sellers always mention the main title and the subtitle, which means that the book can be found everywhere in this spelling (here are two fictitious volumes of a series as an example)

The Magical Books: Book of Spells
The Magical Books: Book of Potions

I would use the following title for these books:

The Magic Books: Book of Spells (The Magic Books #1)

However, another German librarian always deletes the main title and leaves only the subtitle, so like this:

Book of Spells (The Magic Books #1)

This may shorten the title and seems to remove a duplication, but it no longer corresponds to how publishers and booksellers list the book and what is printed on the cover, as is the default in the manuals. There is also another problem: often not only is the main/series title deleted, but the English title is also used as the series title. This leads to some books not being found on Goodreads at all under the title that is emblazoned most prominently on the cover.

Here is an example of a book where the main part is big on the cover, but no longer in the Goodreads title:
https://www.goodreads.com/book/show/6...

Since such cases rarely occur with English books (at most, the smaller subtitle is the series name), there is no specific writing instruction in the manuals. I asked support, but only got the answer: Titles must match the covers.

So I wanted to hear your opinion

[Arenda]

Book of Spells (The Magic Books #1)

Since "The Magic Books" is the series title, this is correct according to GR policy.

but it no longer corresponds to how publishers and booksellers list the book

That doesn't matter. GR has it's own policy for titles with series.

but the English title is also used as the series title.

This is incorrect. In the title field, the series should be in the language of that edition.

and what is printed on the cover, as is the default in the manuals

That is the general instruction. After "Title" there are specific instructions how to handle subtitles and how to handle series.

[lethe]

On the editions page, you can see how the series name is added for the editions in different languages: https://www.goodreads.com/work/editio...

The paperback you linked to has the correct German series title.

The German Kindle edition is incorrect.

[Miss Pageturner]

Ok thank you, just to make that clear this ones are all incorrect too, right?
https://www.goodreads.com/work/editio...

then what is about this case?

Series Name: The Maze Cutter
First Volume: The Maze Cutter: Das Erbe der Auserwählten
Second Volume: The Godhead Complex: Aufbruch nach Alaska

According to the scheme applied, volume one should be called
Das Erbe der Auserwählten (The Maze Cutter #1)

as the main title is the series name. However, for volume two, the main title is no longer the series name, i.e. both the main title and the subtitle would remain
The Godhead Complex: Aufbruch nach Alaska (The Maze Cutter #2)

For the sake of consistency, would you leave the main title for volume 1 as well, or not? Or delete The Godhead Complex from volume two? but then how do people find the book if part of the title isn't searchable?

I wish German publishers wouldn't keep doing this subtitle nonsense, but they think their readers are particularly stupid, who can't find a second volume unless it's called exactly like the first.

[☕ Lachgas ♿]

It would be removing "the maze cutter" for #1 yes.
And keeping "the goodhead complex" for #2

That's not a matter of consistency for me - except you would define consistency as "making a title unnecassarily long and having a :"
(hate that : BS in general in german titles but well...)

And yes on most of the Bridget Jones ones it should go,
the swedisch På spaning med Bridget Jones (Bridget Jones, #2) whould keep it and the turkish maybe but as I don't speak turkish it's more "looks like it might be similar to "harry potter and ...""