Although, when you request a credit limit increase, they do a soft pull. At least, as of last month, I have yet to see it on my report.
it is a hard fast rule that any application for new credit is a hard pull; however the only two exceptions to this is if you receive a pre approval from penfed and are approved, they wont hard pull your credit. (i believe you have to be an active penfed account holder though). the only other partial exception to this is if you are an active amex cardmember, if you apply for another card and get denied as a result, then they wont hard pull your credit.