The KDE Project suggests using Oxygen (preferred - installed by default on leading KDE distros ), Lato (www.latofonts.com/) or Cantarell (abattis.org/cantarell/) typefaces for all printed and screen material. These should be used instead of Bitstream Vera Sans Bold (www.bitstream.com/categories/products/fonts/vera/index.html), which was previously recommended. These are free and open fonts with licenses that are appropriate for KDE materials.
Headlines are either: black; or white on a blue or black background. Sublines and lead-ins can be black on white backgrounds. Copy is always black.
In general the Kabel-Font may only be used uppercase. It may only be used for the term "KDE" itself and related to topics like KDE-EDU, kids and games.
A free look-alike called "Kabel Book" by A. Carr is available at:
Additionally, many Font Companies offer a Kabel font family commercially.
The incorrect use of typography creates confusion and undermines confidence in the brand.