Triggering Term open end home equity line?

Home Equity Line of Credit
Rates from Prime to Prime + 3.50% *
Rate based on loan to value %
Call ____________.

* Is the above index considered a rate triggering term?

I'd say yes. The Commentary to 226.16(b) includes implicit terms in the description of triggering terms. So since you can readily determine APRs from this information, I'd say all the disclosure information is needed.

One comment without looking at the advertising regs: Stating a loan to value implies a specific down payment. With some regulators that will be deemed a triggering term.