From an amateur radio viewpoint there is some meaning as to the origin of W,K and N prefixes. After 1927, the Dept. of Commence, which had jurisdiction over U.S. amateur radio, started to issue 1x3 callsigns beginning with the "W" prefix. Its successor to the regulation of wireless and telephonic communications, the FRC and the FCC, continued that tradition. After WWII, the FCC added a new 10th amateur radio radio district in the CONUS, and that was designated "zero". In the early 1950's, it was becoming apparent that 1x3 callsigns beginning with the prefix "W" were near the point of exhaustion. The FCC than opened up "K" prefix 1x3 callsigns. By the end of the 1950s, "K" prefix 1x3 sequentially issued original callsigns were coming to an end in the populated 2nd (NY-NJ) and 6th (California) radio districts. The FCC than introduced the "WA" prefix for sequential 2x3 callsigns. By 1963-64, "K" prefix 1x3 callsigns were at an end and ALL sequentially issued callsigns were beginning with either WA or WB for Technician and higher classes of licensees.. Novices were issued distinctive callsigns beginning with WN. The Novice license, at the time, was good for ONE year and non-renewable. In 1978, the FCC completely revamped the entire US amateur radio callsign system into four groups. Group A was for amateur extra sequential callsigns-2x1 and 1x2s, Group B was for Advanced Class-2x2s, Group C was for Technician/ General Class-1x3s and Group D was for Novices. Group C started issuing 1x3 callsigns beginning with the "N" prefix. After these "N" prefix calls were exhausted --the FCC went directly to Group D which were "k" prefix 2x3 sequential callsigns that are issued currently. Many newcomers to amateur radio obtain 1x3 vanity callsigns beginning with "W" or "K" as these callsigns imply that the holder is an "oldtimer" in amateur radio licensed at least 55 years ago..
Based on your existing license class, meaning, not all calls are available to all classes of license.
