Why do 2 EPSG Codes exist for the same coordinate system?

Question

I sometimes need to publish data in Gauss-Kruger zone 3 and was wondering why there are now the following EPSG Codes which define this CRS.

1. 31467 - DHDN / 3-degree Gauss-Kruger zone 3
2. 31463 - DHDN / 3-degree Gauss zone 3

The Parameters are identical. Then why 2 Codes?

Answer 1

EPSG:31463 seems to be deprecated and EPSG:31467 is the correct one.

http://spatialreference.org/ref/epsg/dhdn-3-degree-gauss-zone-3/ is stating:

ProjCRS related to inappropriate coordinate system resulting in incorrect axes and name. Use EPSG:31467 instead.

you can see see this, if you compare the AXIS definitions:

PROJCS["DHDN / 3-degree Gauss zone 3 (deprecated)",
GEOGCS["DHDN",
    DATUM["Deutsches_Hauptdreiecksnetz",
        SPHEROID["Bessel 1841",6377397.155,299.1528128,
            AUTHORITY["EPSG","7004"]],
        AUTHORITY["EPSG","6314"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.01745329251994328,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4314"]],
UNIT["metre",1,
    AUTHORITY["EPSG","9001"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",9],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",3500000],
PARAMETER["false_northing",0],
AUTHORITY["EPSG","31463"],
AXIS["X",EAST],
AXIS["Y",NORTH]]

with:

PROJCS["DHDN / Gauss-Kruger zone 3",
GEOGCS["DHDN",
    DATUM["Deutsches_Hauptdreiecksnetz",
        SPHEROID["Bessel 1841",6377397.155,299.1528128,
            AUTHORITY["EPSG","7004"]],
        AUTHORITY["EPSG","6314"]],
    PRIMEM["Greenwich",0,
        AUTHORITY["EPSG","8901"]],
    UNIT["degree",0.01745329251994328,
        AUTHORITY["EPSG","9122"]],
    AUTHORITY["EPSG","4314"]],
UNIT["metre",1,
    AUTHORITY["EPSG","9001"]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",9],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",3500000],
PARAMETER["false_northing",0],
AUTHORITY["EPSG","31467"],
AXIS["Y",EAST],
AXIS["X",NORTH]]