One more interesting feature was the “write lock” switch on the 3.5" ones, a sliding button that covered one of the squared holes on their edges. The floppy drive would sense that and refuse to write on them.
On the 5.25" it was a notch cut on the side (there were punchers for that). To write on a “protected” disk, you’d cover the notch with adhesive tape.
this
One more interesting feature was the “write lock” switch on the 3.5" ones, a sliding button that covered one of the squared holes on their edges. The floppy drive would sense that and refuse to write on them.
On the 5.25" it was a notch cut on the side (there were punchers for that). To write on a “protected” disk, you’d cover the notch with adhesive tape.