little symbols on threads

[GforGraham]

Under each forum beside thread title are some little box icons, found the descriptions for these, err somewhere. In the same area as s thread title are some more boxy icons, et right side. Is there a dscription for these somewhere. The box icons then appear elsewhere without any descriptions I can see. Would need to enter these area as I again find them.
Also some threads show the title boxentirely coloured in. In my case they are shades of green, some pale others brighter shade. They stand out among the remainder of title boxes. Why?

Ta.

 

[removed9556]