480i is the video mode used for standard-definition digital television in the Caribbean, Japan, South Korea, Taiwan, Philippines, Laos, Western Sahara, and most of the Americas (with the exception of Argentina, Paraguay, and Uruguay). The 480 identifies a vertical resolution of 480 lines, and the i identifies it as an interlaced resolution. The field rate, which is 60 Hz (or 59.94 Hz when used with NTSC color), is sometimes included when identifying the video mode, i.e. 480i60; another notation, endorsed by both the International Telecommunication Union in BT.601 and SMPTE in SMPTE 259M, includes the frame rate, as in 480i/30. The other common standard definition digital standard, used in the rest of the world, is 576i. It originated from the need for a standard to digitize analog TV (defined in BT.601) and is now used for digital TV broadcasts and home appliances such as game consoles and DVD disc players. Although related, it should not be confused with the analog "525 lines" resolution, mandated by CCIR Systems M and J and usually paired with NTSC color. This association explains why 480i is sometimes inaccurately called "NTSC", even though NTSC only exists in the analog domain. Technical details For analog NTSC, there are a total of 525 scanning lines per frame of which originally 483 lines were visible (241.5 visible lines per field + 21 lines of vertical blanking per field = 483 + 42 = 525 lines per frame) and later 480 (240 complete lines per field). [For quad video recording systems, the math suggests 15 transverse head passes, each consisting of 16 lines of video, are required to complete one field.] A full frame consists of two fields. One field contains the odd-numbered lines and the other contains the even ones. By convention an NTSC video frame is considered to start with an even field followed by an odd field. The disparity of the line numbering compared to other systems is solved by defining the line numbering to start five equalizing pulses (or 2 and a half lines) earlier than on all other systems, including Systems A (405-line) and E (819-line) even though they had no equalizing pulses, on the first equalizing pulse following an active line or half line. This has the effect of placing a half line of video at the end of the even (first) field and the beginning of the odd (second field). Thus the