I tried to add the series Koakuma Teeri to Kyuuseishu!? (Novel) to BU, but it was rejected and i cant get the reason nor there is a reply as for why it was rejected.

http://myanimelist.net/manga/40731/Koakuma_Teeri_to_Kyuuseishu!

Here is the info of the novel and currently has 6 volumes, you can check those here http://www.mediafactory.co.jp/bunkoj/book_detail/1148 but since its in japanese i dont get what it says.

Also volume 1 of this novel was completely translated by Code-Zero

So why was the series rejected? or is the system that detects something and automatically reject added series for some reason?

Ore no Riaru to Netoge ga Rabukome
To Love-Ru Forever.

Unlike manga series, MU does not allow Novels into the database unless it has an English translation somewhere.

While you have provided that translations do exist, the translation group itself does not exist in the MU database.

You need to add the group and have it approved first before adding the novel and then adding the release.

I've taken the liberty to add the group for you. You just need to wait for an admin to approve it then you can probably add the novel and the release.

You'll know it's approved if you can find the group in search or I get a confirmation and PM you.

Thats false, MU does allow Novels in to the database that dosnt have translations.
https://www.mangaupdates.com/series.html?perpage=50&filter=no_releases&type=novel&orderby=year

here you got more than 50 novels that dosnt have any translations and that no group has picked up.
So thats not why mine got rejected.

Ore no Riaru to Netoge ga Rabukome
To Love-Ru Forever.

Those either accidentally got approved and shouldn't have been, or they were added before we made the policy

A just ruler amongst tyrants

No . I'm pretty sure MU doesn't allow untranslated novels, because that was the reason I was given when I tried adding Katanagatari into the database years ago. Also, it's in the FAQs.

[url]http://www.mangaupdates.com/faq.html?cid=7#item49[/url]

Here's an improved linked removing the licensed novels:
Untranslated Novels

It shows only 3 novels fell through the cracks in the last 5 years and they didn't have "(novel)" on the title.

Mm.... Then how can you know when a novel is being translated if its not asked when you fill up the information??
Also since when is the policy? Because there are novels from 2013 that dont have translations for example

Or do i have to say what group is translating it in the description?

Ore no Riaru to Netoge ga Rabukome
To Love-Ru Forever.

Yes, a Group name is necessary when submitting release information (otherwise people would have an extremely hard time finding the release). Under your 'User CP,' both 'Add Group' and 'Add Release' have a section where you add the Group name and site.

(I think with the system set up here and if you submit all the information correctly, there isn't really a need to add the group information in the 'Description.'
But if the 'Description' summary is from the Group's site, you can add a note at top saying "From [Group Name]:" before adding the 'Description.' Try checking out other releases and series pages in the database here for examples to see what I mean.)