Here is a sampling of the most “popular” packaging variants - please click on the image to make them larger!

Rub vs No Rub. On some bots, its easy to see the presence of the rub sticker through the window, while on some others its not.

Straight line tech specs vs scrambled tech specs.

TM vs R box. Above the right side of the “S” in Transformers, the earlier releases had “TM” while the later ones had “R”.

NGB - stands for no grey border. The early releases didnt have a grey border and had full color between the robot on the box and the windox.

Age Recommendation: This changes a bunch of different ways - the font color and size and the age can vary between 5, 6, and 7.

Copyright - this can change several ways with most common being the corporate name for Hasbro over time.

Assortment - as they changed the lineup between years, fairly often the assortment code would change. It also changes for onpacks like decoys, minispies, patches, etc.