diff --git a/.gitattributes b/.gitattributes
index 56aa7f3307343f58909999e5af9031820f0edfe0..97d86df012693c047268d983f545a526fd62a1a5 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -11,6 +11,7 @@ CAL/CalibrationCommon/lib/__init__.py -text
 CAL/CalibrationCommon/lib/coordinates.py -text
 CAL/CalibrationCommon/lib/datacontainers/__init__.py -text
 CAL/CalibrationCommon/lib/datacontainers/holography_dataset.py -text
+CAL/CalibrationCommon/lib/datacontainers/holography_dataset_definitions.py -text
 CAL/CalibrationCommon/lib/datacontainers/holography_measurementset.py -text
 CAL/CalibrationCommon/lib/datacontainers/holography_observation.py -text
 CAL/CalibrationCommon/lib/datacontainers/holography_specification.py -text
diff --git a/CAL/CalibrationCommon/lib/datacontainers/holography_dataset_definitions.py b/CAL/CalibrationCommon/lib/datacontainers/holography_dataset_definitions.py
new file mode 100644
index 0000000000000000000000000000000000000000..870ea4486f437d25fe1375236bdc765e9714dd9f
--- /dev/null
+++ b/CAL/CalibrationCommon/lib/datacontainers/holography_dataset_definitions.py
@@ -0,0 +1,30 @@
+import numpy
+
+HOLOGRAPHY_DATA_SET_VERSION = 1.0
+
+# Allowed HDS keywords
+HDS_VERSION = "VERSION"
+HDS_MODE = "mode"
+HDS_RCU_LIST = "RCU list"
+HDS_SAS_ID = "SAS id"
+HDS_TARGET_STATION_NAME = "Target station name"
+HDS_TARGET_STATION_POSITION = "Target station position"
+HDS_SOURCE_NAME = "Source name"
+HDS_SOURCE_POSITION = "Source position"
+HDS_OBSERVATION_TIME = "Observation time"
+HDS_ROTATION_MATRIX = "Rotation matrix"
+HDS_ANTENNA_FIELD_POSITION = "Antenna field position"
+HDS_REFERENCE_STATION = "Reference station"
+HDS_FREQUENCY = "frequency"
+HDS_RA_DEC = "RA DEC"
+HDS_DATA = "data"
+
+data_sample_type = numpy.dtype([
+    ('XX', numpy.complex64),
+    ('XY', numpy.complex64),
+    ('YX', numpy.complex64),
+    ('YY', numpy.complex64),
+    ('l', numpy.float64),
+    ('m', numpy.float64),
+    ('t', numpy.float64),
+    ('flag', numpy.bool)])