【help】what does this symbol mean in Fritz12？

Here it is showed as in pict. I've encountered this trapezoidal liked symbol for several times which is very occasionally happend and puzzled me desperately that I do wonder its meaning while searched with no answer in hundreds of  webpages.

Simply just wonder what does this symbol (trapezoial liked one)mean? anyone can help me with this ? Thanks in advance!

i think it means "Better is"

I don´t know for sure, but it always gives me that symbol if the text move is a lot worse than the *trapezoidal* symbol-move...

EDIT: I see now the answer is given in post #4 =) Thanks rooperi!

Great post rooperi !

But still another two more symbol

What does the red square mean? And the last *** with _ mean ?

Ah..too many symbols ...waiting for  the answer ,is there anybody anybody know them all?

That symbol in post#6 (in fritz 8 at least) is nothing to do with chess: rather, it means that there is a tactical puzzle... so if you scroll through the game to this move the program should prompt you to find the best move.

I do.

BTW, the three asterix mean there is a training exercise, as has been mentioned already.

thanks. I wanted to know that too  lol