What about the icons?
The icons are designed to structure the 3Rs Info Hub.
The upper right shows the subtopic.
in vitro | on-a-chip | in chemico | in silico | in vivo | other - lightbulb = course
The lower right informs about the difficulty.
for beginners | intermediate users | experts
The center depicts the type of content.
video | article | webpage | discussion | presentation
The color indicates the R.
replacement | reduction | refinement - exception: red = course