Common uses for a cap with a hole in laboratory settings include:

1. Ventilation: The hole allows for some degree of gas exchange or ventilation while still providing some containment.
2. Insertion of Probes or Instruments: The hole may be used to insert probes or other instruments into the glassware without fully removing the cap.
3. Condensation Control: In setups where condensation needs to be controlled, a cap with a hole can be used to manage the release of gases or vapors.