Article 10 is one of the most important parts of the Magic Prohibition Law, which states that, "magic used for social justice is permitted". This is often exploited numerous times through the series by wizard barristers due to how broad it is, to the point where human characters sometimes comment that it's an easy way for wizards to get away with something. However it is also shown to be held to rather strict standards, at times.
Cecil Sudo complained that her use of magic to defend herself and Moyo against muggers shouldn't have gotten her fined due to Article 10.
After her timely arrival at Kohinata Souta's trial with a witness from the No Face gang, the prosecution says the Cecil must have used magic to apprehend the witness, to which Cecil states that it'd be covered by article 10.
Ageha Chono stated that article 10 made Tobirou Kamakiri's use of illusion magic to impersonate Shizumu Ekusou and Quinn Erari even, since it lead to the capturing of the No Face member and justified verdict for Kohinata.
After the Butterfly Law Offices members used magic against Tei Shimizu to protect Cecil, Ageha nervously states to Quinn that "she thinks the magic law article 10 counts here", to which the latter just responded with a surrendered smile.