Disclosed is a device for encoding information written on a readable surface, the device including a device housing containing at least one ink reservoir, an ink dispensing tip in communication with said at least one ink reservoir; and ink stored in the at least one ink reservoir and configured to flow from the ink dispensing tip, the ink being encodable to include supplemental encoded information, the supplemental encoded information being detectable by at least one detecting sensor when dispensed on the readable surface, wherein the readable surface is any surface that will accept the ink.

Disclosed is a device for encoding information written on a readable surface, the device including a device housing containing at least one ink reservoir, an ink dispensing tip in communication with said at least one ink reservoir; and ink stored in the at least one ink reservoir and configured to flow from the ink dispensing tip, the ink being encodable to include supplemental encoded information, the supplemental encoded information being detectable by at least one detecting sensor when dispensed on the readable surface, wherein the readable surface is any surface that will accept the ink.

Provided is a writing instrument suited to ballpoint pens, marking pens and the like in which a flow pressure of an ink applied to a pen tip is controlled to a fixed level to prevent an ink direct flow phenomenon reverse flow phenomenon. The above writing instrument comprises a pen tip disposed at a front part of an ink tank, an ink received in the ink tank, a follower filled at a rear part of the ink, and a capillary porous member provided with a capillary force, which is arranged at a space part between a rear part of the follower and a rear end part of the ink tank in a state in which the follower is filled, wherein the pen tip is sealed when a cap is put on the writing instrument.

A writing instrument with an operating side, with a writing side with a nib, with a tank which can be filled with liquid writing medium, with a piston, which is movable within the tank, and with an operating element arranged on the operating side for axial adjustment of the piston within the tank. The writing instrument is characterized in that the operating element can be brought by a user from a first axial position, namely an idle position, in which it is held axially in position in particular with locking, into a second axial position which differs axially from the idle position, namely an operating position, in which the operating element has a larger distance to the nib in comparison with the idle position and in which the operating element can be gripped by the user and moved for the axial adjustment of the piston.