Yes, changing rates and fees. Here is what they quoted (what is in bold and italics)
1026.52
(2) Variable rate exception. A card issuer may increase an annual percentage rate when:
(i) The annual percentage rate varies according to an index that is not under the card issuer's control and is available to the general public; and
(ii) The increase in the annual percentage rate is due to an increase in the index.
(3) Advance notice exception. A card issuer may increase an annual percentage rate or a fee or charge required to be disclosed under §1026.6(b)(2)(ii), (b)(2)(iii), or (b)(2)(xii) after complying with the applicable notice requirements in § 1026.9(b), (c), or (g), provided that: (i) If a card issuer discloses an increased annual percentage rate, fee, or
charge pursuant to § 1026.9(b), the card issuer must not apply that rate, fee, or charge to transactions that occurred prior to provision of the notice; (ii) If a card issuer discloses an increased annual percentage rate, fee, or charge pursuant to § 1026.9(c) or (g), the card issuer must not apply that rate, fee, or charge to transactions that occurred prior to or within 14 days after provision of the notice; and (iii) This exception does not permit a card issuer to increase an annual percentage rate or a fee or charge required to be disclosed under § 1026.6(b)(2)(ii), (iii), or (xii) during the first year after the account is opened, while the account is closed, or while the card issuer does not permit the consumer to use the account for new transactions. For purposes of this paragraph, an account is considered open no earlier than the date on which the account may first be used by the consumer to engage in transactions.