Topic: Guitar Tabs Question

I'm trying to learn "Black Water" by the Doobie Brothers and the tab portion shows a capital "D" where the low "E" string is and it shows a lower case "d" where the high "E" string is. All the other strings A,D,G, and  B are where you'd expect them to be. Can someone browse the song and help me out here and show me what the author is trying to tell the reader? Thanks.

Re: Guitar Tabs Question

it means its in double drop d

tune both of the e strings to D

Re: Guitar Tabs Question

The song is probably dorp D tuning.