One of our great British traditions, religious tolerance, has been upheld today.

Sarika Singh has won a High Court discrimination claim against her school which excluded her for breaking the school's "no jewellery" code.

The Sikh teenager was excluded in 2007 after she refused to remove a Kara bangle - a slim steel bracelet - an important symbol of her religious faith. Aberdare Girls' School had claimed that the "no jewellery" policy was fair to all, but the High Court declared that the school was guilty of indirect discrimination under race relations and equality laws.

Mr Justice Silber said that he had been told the Kara bangle was regarded as vital to the Sikh religion. The Judge commented: "In this case there is very clear evidence it was not a piece of jewellery but to Sarika was, and remains, one of the defining focal symbols of being a Sikh."

The question in this case, like that of Lydia Playfoot's last July, is how do you categorise the item in question? Is it jewellery? If so, schools must be consistent in the implementation of their "no jewellery" policies.

Mr Justice Silber himself questioned why expensive watches were allowed at Aberdare Girls School when the simple plain steel kara was not. The school's distinction between types of jewellery seems completely arbitrary.

What are the limits of religious expression and how do we decide? Obviously, religious liberty (like all liberties) can only ever exist within a wider legal and moral framework. If a person's religious faith compels them to act in ways that undermine another's well-being, the exercising of that faith should be restricted.

Concern for the common good must direct our thinking. Is the common good promoted by preserving the freedom of Sarika Singh to wear her bracelet or by preventing her and others from doing so? In today's case, the answer is clearly the former, and we should welcome the ruling.

This article first appeared in The Daily Telegraph Ways and Means blog.