Xtykutl

Wikipedia:

QR code (abbreviated from Quick Response Code) is the trademark for a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan.

Wikipedia

MaxiCode is a public domain, machine-readable symbol system originally created and used by United Parcel Service. Suitable for tracking and managing the shipment of packages, it resembles a barcode, but uses dots arranged in a hexagonal grid instead of bars. MaxiCode has been standardised under ISO/IEC 16023.

Has anything like this kind of 2D matrix barcode been used in spaceflight in some systematic way? Identifiers may exist on object but were used on the ground only, and that would count if it were specific to spaceflight, but more interested in uses where recognition in space, in either manual/handheld beeping or robotic recognition.

The original ISS inventory management system used bar-codes.

The current inventory management system (IMS) has been successful in
keeping track of 96.84% of more than 8,000 items on the Space Station,
and is used to locate hardware required in the crew’s daily
activities, audit consumables to ensure adequate resupply, and plan
future stowage locations. Barcode labels are attached to Space Station
stowage rack locations, each cargo transfer bag (CTB), and individual
items aboard the Space Station—with the exception of items that are
too small to be tagged and consumables such as food, clothing, and
office supplies, which are not individually tracked.

In the 2004-2008 timeframe, a move was afoot to replace the system with a Radio Frequency Identification (RFID) based system. I don't know the outcome of that.

source

Astronaut Garrett Reisman discusses the system here:

"Everything on the station, pretty much everything -- I mean, like
individual pieces of underwear, for example, might not have it to this
detail, but -- almost every major piece of equipment up there has a
barcode on it," shared Reisman.

Shuttle food had bar-codes on it too, but I don't recall them being used in flight, so I suspect they were used for keeping track on the ground.

(personal photo)

Some NASA interns used 2D barcodes as a simulated starscape for developing a navigation system, as per this July 2018 release.

Does actually navigating by the stars count? Probably not, but there are near parallels.

Engineering interns Tristan Schuler, left, and Greta Studier pose with 2D barcodes and a Nano Air-Bearing Simulator prototype that uses the navigation system they developed while at Marshall. Their navigation system is available as open source code on code.nasa.gov. Credits: NASA/Emmett Given