Weird values in the Programming language field (Privátny)

Jak vyvolat chybu: Edit any article, e.g. https://www.itnetwork.cz/…/manage/1537 .

Chybné chování: In the Programming language field, which used to be a string containing e.g. "C#", is the value of "c-sharp-zaklady". It seems to be the parent section full url.

Předpokládané chování: As I remember this field was filled for sections only to represent the programming language which is then used in language sales stats here - https://www.itnetwork.cz/analyzy Originally it should not be filled for lessons. This is rather a topic to investigate and of course I dunno what to fill in there now.