EPSG:1264

COORDINATEOPERATION["BD50 (Brussels) to BD50 (1)",
    VERSION["IGN-Bel"],
    SOURCECRS[
        GEOGCRS["BD50 (Brussels)",
            DATUM["Reseau National Belge 1950 (Brussels)",
                ELLIPSOID["International 1924",6378388,297,
                    LENGTHUNIT["metre",1]]],
            PRIMEM["Brussels",4.367975,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[ellipsoidal,2],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]],
            ID["EPSG",4809]]],
    TARGETCRS[
        GEOGCRS["BD50",
            DATUM["Reseau National Belge 1950",
                ELLIPSOID["International 1924",6378388,297,
                    LENGTHUNIT["metre",1]]],
            PRIMEM["Greenwich",0,
                ANGLEUNIT["degree",0.0174532925199433]],
            CS[ellipsoidal,2],
                AXIS["geodetic latitude (Lat)",north,
                    ORDER[1],
                    ANGLEUNIT["degree",0.0174532925199433]],
                AXIS["geodetic longitude (Lon)",east,
                    ORDER[2],
                    ANGLEUNIT["degree",0.0174532925199433]],
            ID["EPSG",4215]]],
    METHOD["Longitude rotation",
        ID["EPSG",9601]],
    PARAMETER["Longitude offset",4.367975,
        ANGLEUNIT["degree",0.0174532925199433],
        ID["EPSG",8602]],
    OPERATIONACCURACY[0.0],
    USAGE[
        SCOPE["Change of prime meridian."],
        AREA["Belgium - onshore."],
        BBOX[49.5,2.5,51.51,6.4]],
    ID["EPSG",1264]]

proj4.defs("EPSG:1264","+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=longlat +ellps=intl +pm=brussels +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1");

{
    "$schema": "https://proj.org/schemas/v0.7/projjson.schema.json",
    "type": "Transformation",
    "name": "BD50 (Brussels) to BD50 (1)",
    "source_crs": {
        "type": "GeographicCRS",
        "name": "BD50 (Brussels)",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "Reseau National Belge 1950 (Brussels)",
            "ellipsoid": {
                "name": "International 1924",
                "semi_major_axis": 6378388,
                "inverse_flattening": 297
            },
            "prime_meridian": {
                "name": "Brussels",
                "longitude": 4.367975
            }
        },
        "coordinate_system": {
            "subtype": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4809
        }
    },
    "target_crs": {
        "type": "GeographicCRS",
        "name": "BD50",
        "datum": {
            "type": "GeodeticReferenceFrame",
            "name": "Reseau National Belge 1950",
            "ellipsoid": {
                "name": "International 1924",
                "semi_major_axis": 6378388,
                "inverse_flattening": 297
            }
        },
        "coordinate_system": {
            "subtype": "ellipsoidal",
            "axis": [
                {
                    "name": "Geodetic latitude",
                    "abbreviation": "Lat",
                    "direction": "north",
                    "unit": "degree"
                },
                {
                    "name": "Geodetic longitude",
                    "abbreviation": "Lon",
                    "direction": "east",
                    "unit": "degree"
                }
            ]
        },
        "id": {
            "authority": "EPSG",
            "code": 4215
        }
    },
    "method": {
        "name": "Longitude rotation",
        "id": {
            "authority": "EPSG",
            "code": 9601
        }
    },
    "parameters": [
        {
            "name": "Longitude offset",
            "value": 4.367975,
            "unit": "degree",
            "id": {
                "authority": "EPSG",
                "code": 8602
            }
        }
    ],
    "accuracy": "0.0",
    "scope": "Change of prime meridian.",
    "area": "Belgium - onshore.",
    "bbox": {
        "south_latitude": 49.5,
        "west_longitude": 2.5,
        "north_latitude": 51.51,
        "east_longitude": 6.4
    },
    "id": {
        "authority": "EPSG",
        "code": 1264
    }
}

<?xml version="1.0" encoding="utf-8"?>
<Map srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=longlat +ellps=intl +pm=brussels +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	<Layer srs="+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=longlat +ellps=intl +pm=brussels +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1">
	</Layer>
</Map>

INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) values ( 1264, 'EPSG', 1264, '+proj=pipeline +step +proj=axisswap +order=2,1 +step +proj=unitconvert +xy_in=deg +xy_out=rad +step +inv +proj=longlat +ellps=intl +pm=brussels +step +proj=unitconvert +xy_in=rad +xy_out=deg +step +proj=axisswap +order=2,1', 'None');