Whats the purpose of pvec in the qqplot?

In the qqplot documentation it is written that with pvec I can specify the displayed quantiles of the qqplot. But qqplot alway shows me the same amounts of quantiles in the plot. Did I understand the function of pvec wrong? Example: pvec=0.01:0.01:1; qqplot(x,y,pvec); Schouldn't I now see 100 datapoints in the plot? Beacause I always see a lot more datapoints, since I have a much bigger dataset. Thank you very much for help