What is this symbol and how do I turn it off?

[Anonymous]

I was in the middle of trimming some objects when all of a sudden, this symbol started appearing.  It  happens mid command and I can't figure out how it was turned on, or how to shut it off.

I've attached a screen shot.  The circle, arrow and notes are not part of the drawing.  They're to identify what I'm talking about.

Any help would be much appreciated.

[Anonymous]

I think it was the cycle selection option.

[p_mcknight]

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