#1
https://tabs.ultimate-guitar.com/d/disturbed/voices_tab.htm

Verse
|---------------------------------------------|
|---------------------------------------------------7*-----|
|-----------------------------------------------7*--------|
|-----------------------------------------9---|
|-----------------------------------------8---|
|-7-9-7-9-7-9-7-9-3-7-9-7-9-7-9-7-9-|

What do those asterisks next to the 7 mean? I've read the how to read tab sticky but nothing mentioned there about this or in the tab from which this came from. Anyone can help out please?

Thank you
#2
In this instance it's being used to indicate natural harmonics, but yes it would be helpful if that was mentioned in the tab.