You can easy define the approbations directly in aSc Substitutions Online. Just go to menu Settings - Approbation and use a button Add:
You can write there the name and abbreviation of the approbation or it will be defined on the base of your selected subject automatically.
Choose one or more subjects from the list of subjects:
Add the teachers:
If you need, you can also specify the grades or year. These information will help you to determine appropriate replacement for the missing teacher: