I'm not sure if this post doesn't belong here, please feel free to move to the corresponding section.

How can I edit the vocabulary that Plasma 5 uses to verify and correct orthography. It ignores words that are badly written and accepts orthography fails as correct words. I suppose there must be some file with all the accepted words. Is it a human readable, and editable, file? If yes, please, where is it located?
Also, where can I contact to help developers to improve the vocabulary KDE's spell corrector uses?

Thx.