Answer:
As far as I know the decals represent set players accomplishments to date.
example a running back may get a decal for rushing a certain amount of yards
a linebacker may get some for obtaining x amount of tackles etc
each position is different as is each schools milestone for earning the decals
-jlloyd3887-
For FSU the tomahawks with feathers are for academic excellence the tomahawk with out feathers is for major/ important plays on the field