GTC, I can't find the post, but I believe these to be them. Please understand that no one knows for sure if the MMs use such signals but is commonly theorized that they do.
MARKET MAKER SIGNALS; 100 > I need shares 200 > I need shares badly but dont take it down to get em 300 > Take the price down to get shares.... 400 > Trade it sideways based on Supply and Demand 500 > Gap one way or the other, usually to the direction of the 500 trade. Sometimes -if in the middle -keep the price right where it is.