Yep, they are good for study,
but as long as you are aware of their status

The truth shouldn't hurt,
let's face it, it was probably on a document once,
and a kid hacked it off with scissors.
Now you may rue the action, but had he not done so
the example may have been thrown in the bin

Some of the rarest valuable stamps, are nibbled
torn and abused, just part of life.