These include both good taste and decency criteria, and also a variety of technical and even medical constraints (advertisements may not, for example, contain flashing which would set off attacks of photosensitive epilepsy).
Once submitted, the agency's allocated copy group executive will give initial comments on the script, detailing broadcast timing restrictions, advice on appropriate use of specific shots or imagery and requesting substantiation.
An agency will then adapt the script (because it does not comply with broadcast standards or contains a claim which cannot be corroborated) and submit relevant substantiation documents to the Clearcast executive.
Once received and ingested into the Clearcast system, the ad is first checked for 'supers', a process which measures the height (in television lines) of required legal text ('the small print') to ensure it complies.
Some ads fail at this point, and the agency is forced to modify the legal text in order to ensure it complies in terms of line height and duration on screen.
[5] Subsequently, the commercial is screened by a traffic assistant, who checks the ad and guarantees that the accompanying post-production script and relevant consignment details are comprehensive, valid and correct.
Once this process is complete, the ad is allocated to the relevant copy group executive, where it is viewed and placed 'on the reel' for the following day's morning meeting.
Most ads comply (because they are produced as per the initial script), but this viewing serves as a way of spotting otherwise unforeseen problems, such as music which is not permitted or a style of editing which does not show the product in an accurate light.
After the morning meeting (which usually ends at 11:30 am), the copy group return to their desks and pass on feedback to the agencies involved and approve compliant commercials.
A case brought to the High Court by Diomed Direct sought to show that Clearcast's decisions were public functions subject to judicial review.