Waste liquid container, liquid ejection device, and waste liquid collection system

A waste liquid collection system comprising:

• a waste liquid container retaining unit including a retaining compartment;
• and
• a waste liquid container adapted to be inserted into and retained in the retaining compartment in a removable manner, wherein
• the waste liquid container is adapted to be inserted into the retaining compartment in a direction defined as an insertion direction, the waste liquid container is removed from the retaining compartment in a direction that is opposite to the insertion direction and defined as a removal direction, and the insertion direction and a vertical direction both are transverse to a direction defined as a lateral direction;
• the waste liquid container retaining unit includes
• a discharge unit that discharges waste liquid, wherein the discharge unit is located at an innermost part of the retaining compartment,
• a device discharge unit member that biases the discharge unit in the removal direction,
• a device connection terminal located at a position lower than the discharge unit,
• a device contact portion configured to restrict movement of the waste liquid container in the insertion direction by contacting a portion of the waste liquid container when the waste liquid container is in a retained state inserted into the retaining compartment, and
• a removal restriction unit configured to restrict movement of the waste liquid container in the removal direction when in the retained state, wherein the removal restriction unit is located at a position lower than the device connection terminal;
• the waste liquid container includes
• a front wall located at an innermost part of the retaining compartment in the retained state,
• a fitted portion located in the front wall, wherein the discharge unit is fitted into the fitted portion,
• a side wall extending in the removal direction from the front wall in the retained state,
• a container connection terminal that contacts the device connection terminal, wherein the container connection terminal is located in the side wall at a position lower than the fitted portion,
• an insertion restriction portion that contacts the device contact portion in the retained state,
• an engaged portion including a contacted portion that contacts the removal restriction unit in the retained state, wherein the engaged portion is located at a position lower than both of the container connection terminal and the insertion restriction portion in the retained state,
• wherein the engaged portion is located toward an inner side in the lateral direction from the side wall, and the removal restriction unit is receivable in a region located toward an outer side in the lateral direction from the engaged portion when in the retained state.