How do you change your Mod Version, and what on earth is M.m.p do you ask?
Don't worry I have done some digging around and I have found some useful information to help all you great people make sure your mods follow the M.m.p format.
What is MMP?
MMP or (Major . Minor . Patch) is the kind of format that most software developers use when patching or updating. Minecraft uses something similar to this however it seems to be offset by one digit. The Minecraft developers use something like this (? . Major . Minor) the 1 in the first number would be for something like Alpha or Beta I am not sure why they don't use the traditional MMP system it could have something to do with how they release snapshots.
What are Patches?
Patches are bug fixes, patches are mainly to fix issues such as broken features with a minor update.
The patch number is the far right number. 0.0.X
What are Minor Updates?
Minor updates are like your beta version of your mod. you will have several of these before a Major update is release. You should round over the Patch number to 0 when updating the Minor value, For example say you have 1.5.9 and want to update the mod to a minor update you will set the value to 1.6.0.
The minor update number is in the middle 0.X.0.
What are Major Updates?
Major updates should be stable releases kinda like Minecraft 1.12.0 this make sure that people that get your mod are using stable versions of your mod. Minor and patches should round over to 0 when you update your mode to a Major release, for example test say you have 1.5.9 again and want to roll it over to a major update, your new number will be 2.0.0.
The major update number is on the far left of the numbers. X.0.0
I found this site that explains in more technical terms targeted to developers but if you want to look into this and learn more about how it all works this link is a good source for it.