One of colleagues today noted that today he had annoying boxes. When I looked at his screen he had something like this.
These strange annoying boxes are constraints, part of AutoCAD’s parametric system, found under the Parametric Tab on the ribbon (strangely).
In order to use constraints you need to click the INFER constraints button on the bottom left of the status bar. This allows objects drawn in this mode to have the Parametric constraints. This button looks like this
Or this, depending on whether you use icons or not.
Once on you can draw your objects to be constrained. Here I have drawn a rectangle and a polyline. If I move the polyline the rectangle will deform as the polyline and the rectangle are linked or constrained together.
If you do not want this constrain feature on this object anymore you can click on the object and then delete constraints on the ribbon.
Once removed the object returns to a plain old rectangle polyline.
Remember to turn off the INFER constraints button before drawing anything else as all items drawn will have this parametric capability.