Most USA manufactured MREs (both military and civilian) use a 4 digit Julian Date code. Individual MREs may or may not have a date code, same applies to individual components.
See examples below. The first Apack was packed on the 172nd day of 2011.
1348 is the 348th day of 2011.
1306 is the 306th day of 2011.
This code is usually stamped on the MRE box and pouch. The location of the code can vary. The first digit represents the year, and the last three digits represent the day. So, for example, the code 7304 would mean it was manufactured on the 304th day of 2007, or October 31, 2007. Sometimes other letters representing batch numbers will be added to the end of the date code (i.e. 7304C).
You can see on the first example that the code 1172 would mean that it was manufactured in 2011 on June 20th (the 172 day of the year).
The second MRE has a manufacture code of 1348. This would translate to Dec. 13, 2011.
The third MRE's manufacture code is 1306, which means that it was manufactured on Nov. 1, 2011.
Because the official longevity of an MRE is usually less than 10 years, manufacture dates are printed on packages assuming that you will not keep your MREs for longer than this time period. So there is no official way to determine 2001 from 2011, 2002 from 2012 etc.
TTI is the orange sticker on all official military issue MRE cases.
TTI stands for Time Temperature Indicator.
This orange dot is called a Time and Temperature Indicator, or TTI. It tells you about the freshness of the MRE case. When the center dot is darker than the outer ring, that's when the case has gone bad.
In the picture, the center dot is a light orange color, telling you that the contents have been stored properly and are still fresh.
Designed shelf life is 3 years at 80 F. Shelf life is extended with cooler storing temperatures.
Case A vs Case B
Case A contains menus #1-12. Case B contains menus #13-24 (though sometimes substitutions are made at the factory). We've found #5 and #3 in B cases and #23 in A cases.
Each case weighs approximately 22 lbs, average weight of each MRE varies, but net average is 1.8 lbs each.