Great tip, clarkfan! That's pretty expensive money, but as long as it's no/low cost otherwise, a nice option to make available.
jmr5x, I would strongly assume that the 60% is for total Loan To Value. So: (1st mortgage + LOC) / Value = .6 max. If you have a $100k property with a $45k mortgage balance, you'd qualify for a $15k loc.
That's a lot lower (and again, more expensive) than for most owner-occupied options, but as I just posted in another thread, I haven't seen any HELOC option at all on rentals for years.