Or at least one thing that gives people RI scares
When snakes are entering shed, in full shed or just after shedding, the nostril plugs can make some odd breathing sounds and get many snake owners worried about an RI.
Entering shed and during shed, these plugs can get loosened up a bit and vibrate the air exiting the nostrils.
After shedding, the plug(s) may become lodged in the nostril and breeak away from the shed skin, allowing air to continue vibrating upon exhalation.
If you notice some odd sounds from your snake, at the onset of or in shed, give it some time, to ensure the justification for meds. If the sounds continue after shedding, check the shed skin for the nose plugs as there is a good chance that it is what you are hearing instead of a beginning RI.