This is how a form widget looks like for a vocabulary with nested terms, when configured to be rendered as a checkbox list:
For D7, you can use the Taxonomy Term Reference Tree Widget module to improve how this widget works, but I believe that all the bell and whistles it offers would be too much for core. We should just get rid of the dashes from the checkbox labels and add indentation to the checkboxes. It would be so much better and more readable like so:
Related: https://drupal.stackexchange.com/questions/85011/how-to-get-rid-of-the-s... https://drupal.stackexchange.com/questions/121053/add-class-to-sub-taxon... https://www.drupal.org/project/drupal/issues/648264 (Core taxonomy.module issue, pending since 2009 - although for dropdowns)
Recent comments
It is an admin theme that's based upon the bootstrap 3. Maybe it's missing a piece to act as an admin theme?
Add blocks filtering problem
Thank you, Martin and Olaf! I had a feeling that there might be something out there already :) I will check all three options (I will look at porting modules) and report back which one...
Filter by text in "message" in /admin/reports/dblog
The Views Watchdog module for Backdrop "extends the Views module and allows to create custom lists of log entries". On Github, there is also a Wiki page with information about available fields,...
Filter by text in "message" in /admin/reports/dblog