I am trying to understand the differences between the types of Rev changes with ASTM specifications. Some of the changes would include a rev letter change (eg. E140-12, 12a, 12b, ect) and others may only be an editorial change (eg. E140-05, 05e1, etc). Since we are required to have the most recent rev on file, it is my understanding that we would need to purchase every single editorial change. Does anyone know why the editorial change isn't identified the same as an alpha rev change?