When is a 21-inch monitor not a 21-inch monitor? According to the Advertising Standards Authority (ASA), its when you can’t see 21-inches of screen. According to a report on IT news/satire site The Register, the ASA will be making monitor companies state prominently the viewable image area on all adverts from May 1. The Committee of Advertising Practice, the body that draws up the advertising rules and regulations that the ASA enforces, sent out a letter to monitor manufacturers informing them of the changes. Monitors must be advertised with the viewable image area prominently displayed. The letter states that “19-inch CRT monitor (18” viewable)” or “19-inch CRT monitor (not viewable area)” are acceptable but “19-inch CRT monitor” on its own is not. The letter cites the lack of knowledge that CRT size does not equal what users can actually see (and the lack of knowledge of what a CRT was). Placing the viewable area in footnotes isn’t going to wash either. The change in the rules follows the upholding of a complaint against consumer PC makers – Evesham, Time and Tiny – that their monitor advertising was misleading.