The Connection types tab displays all connection types allowed between symbols. The direction is determined by the fact that a connection type is drawn from a Symbol 1 to a Symbol 2.
The Default check box can be used to define a default connection type. You can then place it by double-clicking a cell in the matrix model. There can only be one default connection type for each pair of symbols.
The Display check box controls the visibility in the matrix model. Here, several connection types can be activated for each pair of symbols.
In the Abbreviation column, you can define a letter to signify a connection type. You can then place this connection by selecting a cell in the matrix model and entering its abbreviation.