As author you still have all exploitation rights after publishing on KUPS. That means that you can arbitrarily publish your document anywhere else in printed or electronic form, for example as a monograph, in a journal, as a website.

USB Cologne simply has a non-exclusive simple right of use to your document.

If you intend to publish your document with publisher ensure that you do not cede all of your publication rights to the publisher.
It is important to keep your right for a second publication, especially for a digital one. Otherwise publishing on KUPS will not be possible.

Non-binding information on individual publishing agreements made with publishers are offered by SPARC Author's Addendum and in the author's area on open-access.net.

If you want to upload a document into KUPS which has already been published, it depends on your publishing contract. A lot of publishers allow archiving documents in a non-profit university repository (such as KUPS). This is called the green road of open access or self-archiving.
An overview of policies of different publishers can be found in the SHERPA/RoMEO Listings Publishers’ copyright policies & Self-Archiving - (SHERPA, UK).

Many additional links are summarized on the copyright information page of the Max-Planck Society.

Electronic publications stored on the internet are protected by the German Copyright Act - Urheberrechtsgesetz (UrhG) Thus the copyright of your digital publication is protected to the same extent as a printed publication.

It is not allowed to use electronic documents in an illegal way. Especially intellectual property rights, as laid down in §53 - Vervielfältigung zum privaten und sonstigen eigenen Gebrauch have to be observed.

When uploading documents into KUPS you have the opportunity to define special conditions of use by choosing one of the Creative Commons Licence types. With these you can define more precisely how your document may be used.