I made a posting in my blog which contained the (X)HTML entity ' for a genitive-s in English. In KDE Planet's feed, this apostroph became &apos instead. The entity should have been kept and be visualized by a HTML renderer (browser) as ' Original blog posting: https://t-fischer.dreamwidth.org/8208.html No link available to corresponding entry in planet's feed, look for my posting around June 16, 2019.
The character is now displayed correctly.