The industry standard for MREs is generally 3 year shelf life for domestic and foreign MREs.
In general, foreign MREs use much less preservatives and additives, and also more cheese and dairy items. This is expressed as a "best by date" similar to grocery items.
The MRE itself is dated for the item with the shortest shelf life (let's say cheese). So if the cheese has a 3 year shelf life, the MRE will list that as the best by date for the ENTIRE MRE. Many items inside that same MRE may last much longer like canned food etc.
For the USA rations, the "inspection date" is the date which you should first check the TTI sticker on the USA MRE cases.
In the end, the terminology doesn't really change things. They all have a 3 year shelf life, and all are affected by storage conditions.
When stored in cool dry temperatures, they will outperform their shelf life, and likewise in hot humid storage their shelf life will be shortened.
In general, USA MREs and First Strike Rations will last longer than international MREs.
USA Meal Cold Weather and other freeze dried rations will last even longer.
The Survival MRE - Deep dive into best mini survival kit on the market.
Industry Undercover: Dirty Little Secrets of Civilian MREs
Unlocking History: Lend Lease and the Allure of Vintage Army Rations
Canada Armed Forces IMP MRE
Latvian Armed Forces NATO approved MRE
Spanish Armed Forces ICR Individual Combat Ration Field Test Review
Japan Self Defense Force Type II Improved MRE Field Test Review
French Armed Forces 24 hour RCIR Field Test Review
NATO BCB Multi-Fuel Cooking System Field Test Review
British Armed Forces 24 hour Operational Ration Pack MRE Field Test Review