Insignia

One of the universals across all Transformers continuities has been the use of insignia to differentiate members of respective armies, and sometimes sub-factions within armies or even individuals.

KISS Players
These symbols were used by the Sparkbots in Kiss Play Position.

Brazilian G1
These faction symbols were used in the Brazilian Estrela releases of the Microchange "Mini Car Robo" subline molds.

Beast Wars Neo

 * Blentron

Robots in Disguise
''Takara used this symbol, to represent the Decepticon (Combatron) sub-group in Car Robots- it's an upside-down G2 Autobot symbol, which had been molded into the Scourge toy, a redeco of G2 Laser Optimus Prime. The American version removed them, and used the traditional Decepticon symbol. Though it can be briefly seen in the cartoon, this symbol does not 'exist' in the American version.''
 * Japanese Decepticon

2007 Movie
''For the 2007 Movie, the Autobot and Decepticon factions were almost rendered in the steely gray seen below. Additionally- the Autobot and Decepticons were strongly associated with the colors blue and red, which led to the Autobot symbol appearing in blue in multiple media. Nonetheless the 'official colors' of said symbols remains red and purple.

Others

 * Go-bots
 * My 1st Transformers

Unused concepts
Used for promotion of the comic, not in the actual story. These symbols were seen in concept sketches for the canceled Transtech line.
 * Cobra/Decepticon
 * Transtech