diff --git a/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs.py b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs.py
index 30aa5ffaa..79b6a9375 100644
--- a/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs.py
+++ b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs.py
@@ -28,6 +28,10 @@
     TiffTfsConcepts, TiffTfsToNeXusCfg, get_fei_parent_concepts, get_fei_childs
 from pynxtools.dataconverter.readers.em.utils.image_utils import \
     sort_ascendingly_by_second_argument, if_str_represents_float
+from pynxtools.dataconverter.readers.shared.map_concepts.mapping_functors \
+    import variadic_path_to_specific_path
+from pynxtools.dataconverter.readers.em.subparsers.image_tiff_tfs_modifier import \
+    get_nexus_value
 
 
 class TfsTiffSubParser(TiffSubParser):
@@ -141,18 +145,13 @@ def parse_and_normalize(self):
                   f"TIFF file that this parser can process !")
 
     def process_into_template(self, template: dict) -> dict:
-        self.process_event_data_em_metadata(template)
-        self.process_event_data_em_data(template)
+        if self.supported is True:
+            self.process_event_data_em_metadata(template)
+            self.process_event_data_em_data(template)
         return template
     
-    def process_event_data_em_metadata(self, template: dict) -> dict:
-        """Add respective event_data_em header."""
-        # contextualization to understand how the image relates to the EM session
-        print(f"Mapping some of the TFS/FEI metadata concepts onto NeXus concepts")
-        return template
-
     def process_event_data_em_data(self, template: dict) -> dict:
-        """Add respective heavy image data."""
+        """Add respective heavy data."""
         # default display of the image(s) representing the data collected in this event
         print(f"Writing TFS/FEI TIFF image as a onto the respective NeXus concept")
         # read image in-place
@@ -215,8 +214,14 @@ def process_event_data_em_data(self, template: dict) -> dict:
                 template[f"{trg}/AXISNAME[axis_{dim}]/@units"] = f"{scan_unit[dim]}"
         return template
     
-    def process_event_data_em_state(self, template: dict) -> dict:
-        """Add em-state as they were during the event_data_em event."""
-        # state of the microscope not repeating static/long-valid microscope metadata
-        print(f"Writing TFS/FEI event_data_em state")
+    def process_event_data_em_metadata(self, template: dict) -> dict:
+        """Add respective metadata."""
+        # contextualization to understand how the image relates to the EM session
+        print(f"Mapping some of the TFS/FEI metadata concepts onto NeXus concepts")
+        identifier = [self.entry_id, self.event_id, 1]
+        for nx_path, modifier in TiffTfsToNeXusCfg.items():
+            if (nx_path != "IGNORE") and (nx_path != "UNCLEAR"):
+                trg = variadic_path_to_specific_path(nx_path, identifier)
+                template[trg] = get_nexus_value(modifier, self.tmp["meta"])
+                # print(f"nx_path: {nx_path}, trg: {trg}, tfs_concept: {template[trg]}\n")
         return template
diff --git a/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_cfg.py b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_cfg.py
index e38999b68..0452cc6ad 100644
--- a/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_cfg.py
+++ b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_cfg.py
@@ -195,6 +195,23 @@
                    "ColdStage/Humidity",
                    "ColdStage/SampleBias"]
 
+# there is more to know and understand than just knowing TFS/FEI uses
+# the above-mentioned concepts in their taxonomy:
+# take the example of System/Source for which an example file (instance) has the
+# value "FEG"
+# similar like in NeXus "System/Source" labels a concept for which (assumption!) there
+# is a controlled enumeration of symbols possible (as the example shows "FEG" is one such
+# allowed symbol of the enumeration.
+# The key issue is that the symbols for the leaf (here "FEG") means nothing eventually
+# when one has another semantic world-view, like in NOMAD metainfo or NeXus
+# (only us) humans understand that what TFS/FEI likely means with the symbol
+# "FEG" is exactly the same as what we mean in NeXus when setting emitter_type of
+# NXebeam_column to "cold_cathode_field_emitter"
+# world with the controlled enumeration value "other" because we do not know
+# if FEG means really a filament or a cold_cathode_field_emitter
+
+TfsToNexusConceptMapping = {"System/Source/FEG": "cold_field_cathode_emitter"}
+
 
 def get_fei_parent_concepts() -> List:
     """Get list of unique FEI parent concepts."""
@@ -215,7 +232,8 @@ def get_fei_childs(concept: str) -> List:
     return list(child_concepts)
 
 
-TiffTfsToNeXusCfg = {"/ENTRY[entry*]/measurement/EVENT_DATA_EM_SET[event_data_em_set]/EVENT_DATA_EM[event_data_em*]/start_time": {"fun": "ikz_berlin_apreo_iso8601", "terms": ["User/Date", "User/Time"]},
+# "/ENTRY[entry*]/measurement/EVENT_DATA_EM_SET[event_data_em_set]/EVENT_DATA_EM[event_data_em*]/start_time"
+TiffTfsToNeXusCfg = {"IGNORE": {"fun": "ikz_berlin_apreo_iso8601", "terms": ["User/Date", "User/Time"]},
                      "IGNORE": { "fun": "load_from", "terms": "User/User" },	
                      "IGNORE": { "fun": "load_from", "terms": "User/UserText" },
                      "IGNORE": { "fun": "load_from", "terms": "User/UserTextUnicode" },	
@@ -223,8 +241,8 @@ def get_fei_childs(concept: str) -> List:
                      "IGNORE": { "fun": "load_from", "terms": "System/Dnumber" },
                      "IGNORE": { "fun": "load_from", "terms": "System/Software" },
                      "/ENTRY[entry*]/measurement/em_lab/FABRICATION[fabrication]/identifier": { "fun": "load_from", "terms": "System/BuildNr" },
-                     "/ENTRY[entry*]/measurement/em_lab/EBEAM_COLUMN[ebeam_column]/electron_source/emitter_type": { "fun": "ikz_berlin_apreo", "terms": "System/Source" },
-                     "/ENTRY[entry*]/measurement/em_lab/FABRICATION[fabrication]/vendor": { "fun": "load_from", "terms": "System/Column" },	
+                     "/ENTRY[entry*]/measurement/em_lab/EBEAM_COLUMN[ebeam_column]/electron_source/emitter_type": { "fun": "tfs_to_nexus", "terms": "System/Source" },
+                     "/ENTRY[entry*]/measurement/em_lab/FABRICATION[fabrication]/vendor": "FEI",
                      "IGNORE": { "fun": "load_from", "terms": "System/FinalLens" },
                      "IGNORE": { "fun": "load_from", "terms": "System/Chamber" },
                      "IGNORE": { "fun": "load_from", "terms": "System/Stage" },
diff --git a/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_modifier.py b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_modifier.py
new file mode 100644
index 000000000..dddd59bd3
--- /dev/null
+++ b/pynxtools/dataconverter/readers/em/subparsers/image_tiff_tfs_modifier.py
@@ -0,0 +1,49 @@
+#
+# Copyright The NOMAD Authors.
+#
+# This file is part of NOMAD. See https://nomad-lab.eu for further info.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+"""Utilities for working with TFS/FEI-specific concepts."""
+
+# pylint: disable=no-member
+
+from pynxtools.dataconverter.readers.em.subparsers.image_tiff_tfs_cfg import \
+    TfsToNexusConceptMapping
+
+
+def get_nexus_value(modifier, metadata: dict):
+    """Interpret a functional mapping using data from dct via calling modifiers."""
+    if isinstance(modifier, dict):
+        # different commands are available
+        if set(["fun", "terms"]) == set(modifier.keys()):
+            if modifier["fun"] == "load_from":
+                if modifier["terms"] in metadata.keys():
+                    return metadata[modifier['terms']]
+                else:
+                    raise ValueError(f"Unable to interpret modififier load_from for argument {modifier['terms']}")
+            if modifier["fun"] == "tfs_to_nexus":
+                # print(metadata[modifier['terms']])
+                if f"{modifier['terms']}/{metadata[modifier['terms']]}" in TfsToNexusConceptMapping.keys():
+                    return TfsToNexusConceptMapping[f"{modifier['terms']}/{metadata[modifier['terms']]}"]
+                else:
+                    raise ValueError(f"Unable to interpret modifier tfs_to_nexus for argument {modifier['terms']}/{metadata[modifier['terms']]}")
+        else:
+            print(f"WARNING::Modifier {modifier} is currently not implemented !")
+            # elif set(["link"]) == set(modifier.keys()), with the jsonmap reader Sherjeel conceptualized "link"
+            return None
+    elif isinstance(modifier, str):
+        return modifier  # metadata[modifier]
+    else:
+        return None
diff --git a/pynxtools/dataconverter/readers/shared/map_concepts/mapping_functors.py b/pynxtools/dataconverter/readers/shared/map_concepts/mapping_functors.py
index 6ee855b84..8851e3427 100644
--- a/pynxtools/dataconverter/readers/shared/map_concepts/mapping_functors.py
+++ b/pynxtools/dataconverter/readers/shared/map_concepts/mapping_functors.py
@@ -78,11 +78,9 @@ def apply_modifier(modifier, dct: dict):
                 return load_from_modifier(modifier["terms"], dct)
             if modifier["fun"] == "convert_iso8601":
                 return convert_iso8601_modifier(modifier["terms"], dct)
-        elif set(["link"]) == set(modifier.keys()):
-            # CURRENTLY NOT IMPLEMENTED
-            # with the jsonmap reader Sherjeel conceptualized "link"
-            return None
         else:
+            print(f"WARNING::Modifier {modifier} is currently not implemented !")
+            # elif set(["link"]) == set(modifier.keys()), with the jsonmap reader Sherjeel conceptualized "link"
             return None
     if isinstance(modifier, str):
         return modifier