[CQ-Contest] band plan definition - LSB vs USB

[VE5ZX]

>If your SSB signal is 3 kHz wide...
>And the top of 20 meters is 14.350 MHz...
>And you don't want any of your signal to be transmitted above the top of 
>the band...
>Then your highest dial setting on a properly and accurately calibrated 
>radio would be 14.347 MHz.

In the CQWW contest a number of US stations were sitting on 14150.5 and 
their signals strong in the DX phone band below 14150. In fact, it is almost 
impossible at times to work or hear stations from 14147 to 14150.

Should the same consideration that is given to operating at the upper end of 
the band be used when operating near the DX phone bands on 20 and 15 meters? 
In other words, for example should these station limit their lower frequency 
of operation to 14153?

tnx
Syl - VE5ZX