RTFM! 
As a particular example, consider the bit allocations for message 
type 1, an essential part of almost all FT4 and FT8 QSOs. These 
basic messages usually contain two 28-bit call signs, an optional 
acknowledgment R, and a four-character locator, signal report, RRR, 
RR73, or 73. Table 1 shows that this message type consists of fi elds 
with the tags c28, r1, c28, r1, R1, g15, and i3. The r1
fi elds are normally 0; the value 1 implies a /R call sign suffi x to 
indicate “rover” status in a North American VHF contest. 
4FQD是对的,以上内容摘自FT4 and FT8 Communication Protocol,  /R后缀的含义是北美VHF竞赛中用来表示漫游(rover)状态。