What are the special features of connections? 

Different anchor points on objects are offered for selection depending on the connection type.

The selection of anchor points for an object can be restricted according to the method, e.g., for connections from the Entity type to the Generalization object type in eERM type models. While the is supertype of connection type can be drawn only from the entity type to the top of the generalization type, the is subtype of connection type can be attached only to the bottom of the generalization type.

If you have set a grid, the number of connection anchor points and the alignment of connections are affected by the grid width. The greater the grid width you set, the fewer connection anchor points will be offered.

If you have enabled special grid mode, connections will be arranged with half the grid width.