Hi Donald and welcome. MOS = Modular Optics System to accept Red Dot Optics and Agoge is just a name for the Green Colored Shide coating and the Cobalt frame color. Cheers and stay safe!

I get what you're saying. Sometimes it seems like you're trying to decipher a code. If there is a specific item you are referring to though, just ask your question again with the item.

Donald, no handgun specified. If you mean in general, Bud's uses abbreviations in their listings that at times can be confusing.
If you are referring to a specific item, please re-post with item name/model number.
Stay safe & have a great day!