In A Practitioner's Guide to Ethical Decision Making when they refer to Justice it means:

a$.$ You must treat everyone the same, because you need to make sure that everyone is equal.

b$.$ That you must treat everyone differently because everyone is different.

c$.$ If you treat an individual differently you must have a good rationale $($reason$)$ that explains the need for a different approach.

d$.$ That you are responsible for making sure you clients' are always treated fairly.