I always have looked at it as a 'pin' icon, but you are right: it looks like a 'key' too.
Anyway, it means that you have set custom options (e.g. optimizations) for that file, see https://mcuoneclipse.com/2012/07/30/icon-and-label-decorators-in-eclipse/
You can reset it to the defaults, see above article.
I hope this helps,
Erich
I always have looked at it as a 'pin' icon, but you are right: it looks like a 'key' too.
Anyway, it means that you have set custom options (e.g. optimizations) for that file, see https://mcuoneclipse.com/2012/07/30/icon-and-label-decorators-in-eclipse/
You can reset it to the defaults, see above article.
I hope this helps,
Erich