Coinciding with the International Congress on Radiology, which was held for the first time in Delhi recently, the Department of Posts issued a commemorative postage stamp.

The first Congress sponsored by International Society of Radiologists (ISR) was held in London in 1922. The Indian association, which was registered in 1937, has over 3,500 members with 16 branches all over India. The society works for advancement of the practice of Radiology, Radiation science and Radiation protection.

The first day cover released on the occasion of the radiology congress depicts Dr L H Athle, Dr Diwan Chand Aggarwal, Dr Rama Rau, Dr Mihir Mitter -- pioneers in radiation therapy in India.

Another significant philatelic release happenedaround the same time. A stamp was released to mark the occasion of the first Congress of the International Board of Books for the Young (IBBY) held in India.

IBBY, which is committed to bring children and books together, has constituted `Little Nobel Prize' for outstanding contribution to children's literature. In that context, the stamp centred around IBBY will be valued. The stamp, in the denomination of Rs 11, projects the aims and ideas of IBBY by depicting a child engrossed in a book.

According to Madhukar Jhingan, senior philatelists who have won Golds at international exhibitions do not go in for new releases. ``Professional collectors have interest in rare stamps. Whatever is common and easily available does not interest them,'' adds Jhingan. He explains: ``An amateur collector's preference is themes. They collect according to themes, though some philatelists collect all the stamps brought out.''

Offering an interesting view point, he says that design and colour schemes attract even anon-collector. And some stamps, which do not have any specific theme but are designed beautifully with creatively researched first-day covers (FDC), impel buyers and collectors to have them in their collections.

In that category belongs the stamp of Bhai Kanhaiyaji, who sacrificed his life for the service of humanity. The stamp shows him spreading the message of universal brotherhood. The stamp, in the denomination of Rs 2, is beautifully designed.

The stamp showing the `Fourth Battalion Brigade of the Guards' issued recently is a collector's item. The multi-coloured `first-day cover' depicts the gallantry awards, Victoria Cross, Param Vir Chakra, Mahavir Chakra, Vir Chakra that it has won. The Battalion 4 Guards (I Rajput) was raised as part of the Bengal Army on September 15, 1798, at Sasaram, Bihar.

As far as philatelic value is concerned, the stamps on lesser known personalities do not have a wide market. Also such stamps do not have much value for foreign collectors. As a contrast, stamps oninternational themes have a good market nationally and internationally, Jhingan opines. ``Only a hard core philatelist, one who collects all stamps, will collect stamps on personalities.''

The other stamp releases of the month are commemorative stamp on Dr Tristao Braganza Cunha, who fought for the freedom of Goa and for its merger with the independent India. Released on September 26, the stamp of Rs 2 denomination remembers the Goan humanist who was honoured by the World Peace Council in Stockholm in 1959 posthumously. On September 30, the department released a commemorative stamp on the birth anniversary of Janeneta Hijam Irawat Singh, a pioneer in social reforms.