as public broadcaster RTBF and commercial broadcaster RTL-TVI, use the bottom right corner of the screen, in contrast to French-language TV channels in France, Switzerland, etc., which use the top right or left corner. Brazil In Brazil, digital on-screen graphics were introduced in the mid-1990s and are always used by all channels (free and pay). In most free-to-air channels, the logos are located on the bottom-right-hand corner of the screen (except for RedeTV!, TV Gazeta, Rede Bandeirantes, and GloboNews, whose logos are placed on the top right corner of the screen, and for TV Brasil, the top left corner (formerly the top right corner); TV Cultura's logo moved from top left corner to bottom right corner of the screen in 2009) and in all free channels they are usually transparent, but if some program or event is being broadcast live or exclusive or if some archived footage is shown, they become colorful. Most pay channels usually have the logos on the top right corner of the screen. In some pay channels, the logos appear even in commercial breaks, but they become transparent in this situation. Cambodia Cambodian TV channels introduced DOGs in 1995. Like Thailand, all of logos are full-color and displayed on the top-right corner of the screen. Some channels such as TV5 hide their logos during commercial breaks. Canada Logo bugs are used by Canadian broadcasters in a nearly identical fashion to U.S. broadcasters. However, a complication emerges when Canadian broadcasters simulcast U.S. programming (a frequent practice among broadcast television networks, intended to invoke the simultaneous substitution rules requiring TV providers to substitute the feeds of U.S. broadcast channels with those of local, Canadian broadcast channel, if they are airing identically scheduled programming). While pre-recorded programs (e.g. dramas, sitcoms) can be delivered to the broadcaster by their distributor and played out locally (without depending on taking a feed from a U.S. network), live programs may not always have a clean feed available that is free of the U.S. network's bugs and imaging, necessitating the use of a dirty feed from the network instead. In these scenarios, some channels—including, most frequently, CTV and CTV Two, as well as its Bell Media sister channels—covered the U.S. network's bug with their own, opaque logo. However, Bell has since ceased this practice, and the majority of broadcasters "co-brand" the dirty feed by placing their own bug in a different corner of the