<P> Starting in 1948 by Bert Nelson and Cordner Nelson, Track and Field News became the leader in creating and defining abbreviations in this field . But these abbreviations have also been adopted by, among others, the IAAF; the world governing body, various domestic governing bodies, the Association of Track and Field Statisticians, the Association of Road Racing Statisticians, the Associated Press and the individual media outlets who receive their reports . These abbreviations also appear in Wikipedia . </P> <P> Almost all races record a time . Evolving since experiments in the 1930s, to their official use at the 1968 Summer Olympics and official acceptance in 1977, fully automatic times have become common . As this evolution has occurred, the rare early times were specified as FAT times . As they are now commonplace, automatic times are now expressed using the hundredths of a second . Hand times (watches operated by human beings) are not regarded as accurate and thus are only accepted to the accuracy of a tenth of a second even when the watch displays greater accuracy . If the mark was set before 1977, a converted time to the tenth was recorded for record purposes, because they did not have a system to compare between the timing methods . Frequently in those cases there is a mark to the 100th retained for that race . Over this period of evolution, some reports show hand times also followed with an "h" or "ht" to distinguish hand times . </P> <P> With two different timing methods came the inevitable desire to compare times . Track and Field News initiated adding . 24 to hand times as a conversion factor . Many electronic hand stopwatches display times to the hundredth . Frequently those readings are recorded, but are not accepted as valid (leading to confused results). Some low level meets have even hand timed runners and have switched places according to the time displayed on the stopwatch . All of this is, of course, wrong . Hand times are not accurate enough to be accepted for record purposes for short races . Human reaction time is not perfectly identical between different human beings . Hand times involve human beings reacting, pushing the stopwatch button when they see the smoke or hear the sound of the Starting pistol, then reacting (possibly anticipating) the runner crossing the finish line . The proper procedure for converting hand times would be to round any hundredths up to the next higher even tenth of a second and then add the . 24 to get a time for comparison purposes only . But many meets displayed the converted marks accurate to the hundredth making the results look like they were taken with fully automatic timing . In these cases, some meets have displayed a 4 or a 0 in the hundredths column for all races . When detected, reports of these times are followed by a "c" or' to indicate converted times . </P> <P> Road race times are only considered accurate to a full second . To distinguish a full second time with hours, from a minute time with hundredths of a second, colons are used to separate hours from minutes, and minutes from seconds . A period is used to separate seconds from hundredths of a second . </P>

What does c mean in track and field