Jokes about people's age are commonly heard in the workplace, from gags about hitting 30 to being over the half-way mark to retirement. The fact is that a fair number of people enjoy teasing friends, family and co-workers about being over the hill. But the word a joke begins to spell if it starts to cross the borderline of offence is t-r-o-u-b-l-e.

Minter Ellison Rudd Watts employment partner Greg Cain gave the example of a Muslim employee in the UK, who received a 40th birthday card from his colleagues saying he was "too old" to be a "terrorist". He did not feel very flattered by this, and complained that he was discriminated against on the basis of race and religion. The matter eventually went to the Employment Tribunal in the UK, where the employee won a settlement worth thousands of pounds.

This is an extreme case - typically insults do not mix race or religion with age. However, this provides a clear example of what can eventuate from a careless comment.

In the case of dismissal, implicit age discrimination can leave workers and the employer open to litigation, namely when an older staff member is made redundant or sacked, he or she can use examples of age discrimination to argue that something else was involved.