I was wondering whether and how it is possible to add meta information to the application found when using the search box. Every time I intended to use for instance Okular I'd type 'PDF' to search for it but wondering why Okular wouldn't turn up (see image below).
One way that works is via the menu configuration..
Mouse right-click on the menu button and click Configure..:
Click Open the menu editor:
Within the opened editor, go to the application of interest and open Properties where additional information can be added to the Comment box:
Now, searching for this comment is possible via the search box:
Interesting would be still where this information is stored file-wise. That, I couldn't figure out yet. I tried using
grep but I couldn't find any matching file with the comment.
DISCLAIMER: I had an epiphany while preparing my question so I provide the answer as well.