Sources for the images:
- Information.svg by User:Bobarino:
  https://commons.wikimedia.org/wiki/File:Information.svg
- Warning.svg by User:Ezekiel63745 
  https://commons.wikimedia.org/wiki/File:Information_orange.svg
- Important.svg originally from David Vignoni
  https://commons.wikimedia.org/wiki/File:Nuvola_apps_important.svg 
- Critical.svg by User:Stannered
  https://commons.wikimedia.org/wiki/File:Stop_x_nuvola.svg