Have U ever heard about LPG gas cylinder's expiry date....!!

Have U ever heard about LPG gas cylinder's expiry date....!!
I also didn't know how to find LPG cylinder's expiry date,until
recently when i came to know how itz done from a freind of mine..

Expired Cylinders are not safe for use and may cause accidents. In this
regard please be cautious at the time of accepting any LPG cylinder
from the Vendor.

Here is how we can check the expiry of LPG cylinders:

On one of three side stems of the cylinder, the expiry date is coded
alpha numerically as follows A or B or C or D and some two digit number
following this e.g. D06.

The alphabets stand for quarters -
A for March (First Qtr),
B for June (Second Qtr),
C for Sept (Third Qtr), &
D for December (FourthQtr).
The digits stand for the year till it is valid.
Hence D06 would mean December qtr of 2006.