Light novels can be added to the website if they meet all the following criteria:
The light novel must be of Japanese origin.
The light novel is specified as being such by the publisher, author, or the majority of major retailers.
Example light novel labels include things such as:
The Monogatari Series toes the line between appearing as a hard or light novel. It is published in Kodansha BOX, which is a hybrid label, but the work is mixed media (contains illustrations) and is mostly labeled as a light novel by the general community in both Japan and overseas (readers, large retailers etc).