Some of them are buried back in the attic where there’s no headroom. My understanding is that generally, IC-rated are silver inside and nopn-IC are white, but that this isn’t always true. If it’s inaccessible from above, is there any way to be sure from below?
I would not assumme that, most of the reccessed cans I see, the label is inside the can, but to view it means taking out the lamp and the housing trim.
If you click on the fixture below, you will see where the label is most times.
Hope this helps.