Assistant Superintendent Chua Kung Young, 39, has been with the police force for 18 years, but his promotion last June was especially dear to him.

His new rank meant that ASP Chua, previously a personal security officer (PSO) for President Tony Tan Keng Yam, finally qualified to apply for a post as an honorary aide-de-camp (HADC) in the Office of the President - a job he had wanted since his NS days.

"Now I'm two-in-one," he joked. "I can work with my counterparts in the PSO team because I know their job."

The HADCs, along with three full-time aides-de-camp (ADCs), help to organise and support official events.

Yesterday, Dr Tan formally appointed 102 HADCs - 22 of them new to the corps - in a ceremony at the Istana. He also appointed one new full-time ADC - Major Valerie Chia Hing Ee, 39, from the air force.

Members of the HADC Corps come from all branches of the Singapore Armed Forces, as well as the police and Singapore Civil Defence Force, and include regular officers and NSmen. There are 19 NSmen in the corps.

In the past, only regulars could serve in the corps. At the ceremony, Dr Tan thanked the NSmen who have chosen to serve, on top of their national service reservist duties.

He said: "NSmen are a valued group of officers as they bring with them not just experiences in the uniformed service, but also their corporate experiences in their day jobs."

One such newcomer is ASP (NS) Teo Congde, 29 - by day, he is a product development assistant manager at SIA Engineering.

Undeterred by having to use his personal leave when he is deployed as an HADC - which can be several times a month - ASP (NS) Teo said: "Being able to serve and be part of the team, I think I will build up another group of friends... and the experience of seeing how diplomacy is done."

After his speech, Dr Tan presented tokens of appreciation to the two longest-serving NSmen in the HADC Corps - Colonel (NS) Lim Jit Mee, 51, an HADC for 15 years, and Deputy Assistant Commissioner (NS) Lionel Chai Yee Yuen, 50, who has served for 10.

Dr Tan also called attention to those who started their careers without a degree.

These officers "may have taken an alternative pathway to join us", he said, but their journey "adds diversity and enriches the collective skills and professional experience of the HADC Corps".