See 226.26(d):
(d) Additional requirements for home equity plans. (1) Advertisement of terms that require additional disclosures. If any of the terms required to be disclosed under section 226.6(a)or (b) or the payment terms of the plan are set forth, affirmatively or negatively, in an advertisement for a home equity plan subject to the requirements of section 226.5b, the advertisement shall also clearly and conspicuously set forth the following:
(i) Any loan fee that is a percentage of the credit limit under the plan and an estimate of any other fees imposed for opening the plan, stated as a single dollar amount or a reasonable range.
(ii) Any periodic rate used to compute the finance charge, expressed as an annual percentage rate as determined under section 226.14(b).
(iii) The maximum annual percentage rate that may be imposed in a variable-rate plan.