If the telling of secrets or offenses is purposeful, minute details are usually left out as not to appear to be directly telling.
It is indirectly snitching.
"I see this offensive picture is still up. I recall other member's being banned for posting such a thing."
This person is dry snitching on the person that posted the offensive picture. The person is not directly named (a minute detail) and a direct action is not actually being suggested.
"Stop dry snitching. You are going to get him banned"
ex #2- "If you got what I need then set it up. I don't wanna hear about. Don't tell me nothin except when you can get me what what I need and what you need in return because otherwise you are guilty of DRY SNITCHING!"