A liquid cartridge configured to be inserted into a cartridge-attachment section, comprising: a casing comprising: a liquid chamber storing liquid therein; a liquid passage extending in a first direction crossing a gravitational direction from a liquid chamber in an upright posture of the liquid cartridge; and a top surface (39, 91) facing upward in the upright posture and formed with a recess defining a bottom portion; a movable member having a light blocking portion configured to block or attenuate light emitted from the cartridge-attachment section and traveling in a widthwise direction (55, 56) crossing the first direction and the gravitational direction in the upright posture, the light blocking portion in the upright posture being configured to move between a first position and a second position, the light blocking portion in the second position being closer to the bottom portion than the light blocking portion in the first position is to the bottom portion, at least a part of the light blocking portion in the first position being positioned above the top surface in the upright posture; and an urging member (69, 70, 66A) configured to urge the movable member toward the first position; characterised in that: the urging member is positioned at the recess; and the movable member defines a first portion accommodated in the recess in the first position, and defines a second portion accommodated in the recess in the second position, the first portion having a volume smaller than a volume of the second portion. a casing comprising: a liquid chamber storing liquid therein; a liquid passage extending in a first direction crossing a gravitational direction from a liquid chamber in an upright posture of the liquid cartridge; and a top surface (39, 91) facing upward in the upright posture and formed with a recess defining a bottom portion; a liquid chamber storing liquid therein; a liquid passage extending in a first direction crossing a gravitational direction from a liquid chamber in an upright posture of the liquid cartridge; and a top surface (39, 91) facing upward in the upright posture and formed with a recess defining a bottom portion; a movable member having a light blocking portion configured to block or attenuate light emitted from the cartridge-attachment section and traveling in a widthwise direction (55, 56) crossing the first direction and the gravitational direction in the upright posture, the light blocking portion in the upright posture being configured to move between a first position and a second position, the light blocking portion in the second position being closer to the bottom portion than the light blocking portion in the first position is to the bottom portion, at least a part of the light blocking portion in the first position being positioned above the top surface in the upright posture; and an urging member (69, 70, 66A) configured to urge the movable member toward the first position; characterised in that: the urging member is positioned at the recess; and the movable member defines a first portion accommodated in the recess in the first position, and defines a second portion accommodated in the recess in the second position, the first portion having a volume smaller than a volume of the second portion.