What does this icon in Eclipse mean?

Question

I am referring specifically to the green plus sign in the screenshot below.

[edit] This is taken from "Outline" view, and I am coding in Java.

Answer 1

This might help: What do the icons in Eclipse mean?

From the icon index, the plus means add, the C means public class, and the warning means that there is a java element warning.

So from what I can assume, it means you can add a new public class, but is warning you of possible problems with your current project.