Flashback MD Taylor Downing sees reversioning as one of TV's greatest hidden skills.

We're just passed a milestone. Last month Flashback delivered the 2000th hour of reversioned programming for The History and The Biography Channels. We've had the contract since 1996, and we're very proud of these 2000 hours. We're also proud of being experts in what is one of the invisible arts of modern TV.

As TV production is increasingly made for an international market, so the need to reversion programmes to suit the tastes of national viewers becomes paramount. This is as relevant to Channel 4 or the BBC as it is to a digital channel. What works perfectly for a US audience - the style of language, the tone of the commentary, the use of music - feels alien to UK viewers. What works in Germany or Australia often doesn't fit here.

To reversion successfully, a company has to be geared primarily to original production. Flashback engages producers like Sian Williams, Sarah Booth and Jenni Pozzi for The History Channel - all distinguished programme-makers who enjoy adapting a programme that works in one territory into a documentary that works well here. It's not a job for trainees.

Secondly, you have to have excellent management systems. Reversioning can be high-volume butiit is also low-margin work. You need to be on top of costs and every aspect of the process. A tiny overspend can make the difference between making or losing money. Companies without this expertise should stay away.

Finally, you need excellent technical back-up: problems that come with tapes with missing tracks, audio that isn't as it should be and timecode that doesn't match the script are legion.

What's the value of a successful reversion? For terrestrial broadcasters, buying in programmes as acquisitions leaves more money for original commissions. Russia Land of the Tsars was a huge success in the US. Our very different UK version, with new interviewees and more in-depth storytelling worked well for C4. For a niche cable, satellite or digital channel, reversioning is an opportunity to impose its own style or attitude on bought-in programmes: have your own voices reading commentaries; rewrite in your own distinctive style.

Produce globally; reversion locally. That should be the mantra.