There is always a conflict between recommended frequencies in North America vs those recommended in Europe.
Many Pixie and RockMite kits are supplied with 7023 kHz crystals. However, in Europe the centre of QRP activity on 40m CW is 7030 kHz. (7023 kHz is used by RAOTA for their weekly CW nets ... not QRP).
I think part of the problem is that, in the USA, different classes of license have different frequency allocations.