Does the code permit bare incandescent lamps to be installed in porcelain keyless or porcelain pull-chain lampholders?

Yes, the code generally permits bare incandescent lamps to be installed in porcelain keyless or porcelain pull-chain lampholders, as these fixtures are designed to safely hold such lamps. However, it's important to ensure that the installation complies with local electrical codes and safety standards, which may have specific requirements or restrictions regarding the use of bare lamps. Always consult the relevant electrical code or a qualified electrician for confirmation.