So, we are now in 2K6? NO, we have a 594 years wait for the year 2600.
This is a way of saving the effort of writing a single character (and getting it wrong). The correct use of this notation moves the unit prefix (K, M, u) to the decimal point location to eliminate printing errors causing it to not be seen.
It is most commonly used in Electronics, e.g. 2.3k would be 2k3, 4.7A (Amps) would be 4A7, and 0.0047F would be 4m7F.
Hopefully this will die out by 2k010 :o)