diff --git a/docs/metadata-workflow.rst b/docs/metadata-workflow.rst
--- a/docs/metadata-workflow.rst
+++ b/docs/metadata-workflow.rst
@@ -69,7 +69,11 @@
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Intrinsic metadata is extracted from files provided with a project's source
-code, and translated using `CodeMeta`_'s `crosswalk table`_.
+code, and translated using `CodeMeta`_'s `crosswalk table`_; which is vendored
+in :file:`swh/indexer/data/codemeta/codemeta.csv`.
+Ecosystems not yet included in Codemeta's crosswalk have their own
+:file:`swh/indexer/data/*.csv` file, with one row for each CodeMeta property,
+even when not supported by the ecosystem.
 
 All input formats supported so far are straightforward dictionaries (eg. JSON)
 or can be accessed as such (eg. XML); and the first part of the translation is
diff --git a/swh/indexer/codemeta.py b/swh/indexer/codemeta.py
--- a/swh/indexer/codemeta.py
+++ b/swh/indexer/codemeta.py
@@ -9,7 +9,7 @@
 import json
 import os.path
 import re
-from typing import Any, List
+from typing import Any, Dict, List, Set, TextIO, Tuple
 
 from pyld import jsonld
 import rdflib
@@ -66,7 +66,15 @@
     return uri
 
 
-def _read_crosstable(fd):
+def read_crosstable(fd: TextIO) -> Tuple[Set[str], Dict[str, Dict[str, rdflib.URIRef]]]:
+    """
+    Given a file-like object to a `CodeMeta crosswalk table` (either the main
+    cross-table with all columns, or an auxiliary table with just the CodeMeta
+    column and one ecosystem-specific table); returns a list of all CodeMeta
+    terms, and a dictionary ``{ecosystem: {ecosystem_term: codemeta_term}}``
+
+    .. _CodeMeta crosswalk table: <https://codemeta.github.io/crosswalk/
+    """
     reader = csv.reader(fd)
     try:
         header = next(reader)
@@ -75,7 +83,9 @@
 
     data_sources = set(header) - {"Parent Type", "Property", "Type", "Description"}
 
-    codemeta_translation = {data_source: {} for data_source in data_sources}
+    codemeta_translation: Dict[str, Dict[str, rdflib.URIRef]] = {
+        data_source: {} for data_source in data_sources
+    }
     terms = set()
 
     for line in reader:  # For each canonical name
@@ -101,7 +111,7 @@
 
 
 with open(CROSSWALK_TABLE_PATH) as fd:
-    (CODEMETA_TERMS, CROSSWALK_TABLE) = _read_crosstable(fd)
+    (CODEMETA_TERMS, CROSSWALK_TABLE) = read_crosstable(fd)
 
 
 def _document_loader(url, options=None):
diff --git a/swh/indexer/data/Gitea.csv b/swh/indexer/data/Gitea.csv
--- a/swh/indexer/data/Gitea.csv
+++ b/swh/indexer/data/Gitea.csv
@@ -66,11 +66,3 @@
 issueTracker,
 referencePublication,
 readme,
-,
-,
-,
-,
-,
-,
-,
-,
diff --git a/swh/indexer/metadata_dictionary/composer.py b/swh/indexer/metadata_dictionary/composer.py
--- a/swh/indexer/metadata_dictionary/composer.py
+++ b/swh/indexer/metadata_dictionary/composer.py
@@ -8,7 +8,7 @@
 
 from rdflib import BNode, Graph, Literal, URIRef
 
-from swh.indexer.codemeta import _DATA_DIR, _read_crosstable
+from swh.indexer.codemeta import _DATA_DIR, read_crosstable
 from swh.indexer.namespaces import RDF, SCHEMA
 
 from .base import JsonMapping, SingleFileIntrinsicMapping
@@ -20,7 +20,7 @@
 COMPOSER_TABLE_PATH = os.path.join(_DATA_DIR, "composer.csv")
 
 with open(COMPOSER_TABLE_PATH) as fd:
-    (CODEMETA_TERMS, COMPOSER_TABLE) = _read_crosstable(fd)
+    (CODEMETA_TERMS, COMPOSER_TABLE) = read_crosstable(fd)
 
 
 class ComposerMapping(JsonMapping, SingleFileIntrinsicMapping):
diff --git a/swh/indexer/metadata_dictionary/dart.py b/swh/indexer/metadata_dictionary/dart.py
--- a/swh/indexer/metadata_dictionary/dart.py
+++ b/swh/indexer/metadata_dictionary/dart.py
@@ -8,7 +8,7 @@
 
 from rdflib import RDF, BNode, Graph, Literal, URIRef
 
-from swh.indexer.codemeta import _DATA_DIR, _read_crosstable
+from swh.indexer.codemeta import _DATA_DIR, read_crosstable
 from swh.indexer.namespaces import SCHEMA
 
 from .base import YamlMapping
@@ -19,7 +19,7 @@
 PUB_TABLE_PATH = os.path.join(_DATA_DIR, "pubspec.csv")
 
 with open(PUB_TABLE_PATH) as fd:
-    (CODEMETA_TERMS, PUB_TABLE) = _read_crosstable(fd)
+    (CODEMETA_TERMS, PUB_TABLE) = read_crosstable(fd)
 
 
 def name_to_person(name):
diff --git a/swh/indexer/metadata_dictionary/gitea.py b/swh/indexer/metadata_dictionary/gitea.py
--- a/swh/indexer/metadata_dictionary/gitea.py
+++ b/swh/indexer/metadata_dictionary/gitea.py
@@ -8,7 +8,7 @@
 
 from rdflib import RDF, BNode, Graph, Literal, URIRef
 
-from swh.indexer.codemeta import _DATA_DIR, _read_crosstable
+from swh.indexer.codemeta import _DATA_DIR, read_crosstable
 from swh.indexer.namespaces import ACTIVITYSTREAMS, FORGEFED, SCHEMA
 
 from .base import BaseExtrinsicMapping, JsonMapping, produce_terms
@@ -20,7 +20,7 @@
 GITEA_TABLE_PATH = os.path.join(_DATA_DIR, "Gitea.csv")
 
 with open(GITEA_TABLE_PATH) as fd:
-    (CODEMETA_TERMS, GITEA_TABLE) = _read_crosstable(fd)
+    (CODEMETA_TERMS, GITEA_TABLE) = read_crosstable(fd)
 
 
 class GiteaMapping(BaseExtrinsicMapping, JsonMapping):
diff --git a/swh/indexer/metadata_dictionary/nuget.py b/swh/indexer/metadata_dictionary/nuget.py
--- a/swh/indexer/metadata_dictionary/nuget.py
+++ b/swh/indexer/metadata_dictionary/nuget.py
@@ -9,7 +9,7 @@
 
 from rdflib import RDF, BNode, Graph, Literal, URIRef
 
-from swh.indexer.codemeta import _DATA_DIR, _read_crosstable
+from swh.indexer.codemeta import _DATA_DIR, read_crosstable
 from swh.indexer.namespaces import SCHEMA
 from swh.indexer.storage.interface import Sha1
 
@@ -19,7 +19,7 @@
 NUGET_TABLE_PATH = os.path.join(_DATA_DIR, "nuget.csv")
 
 with open(NUGET_TABLE_PATH) as fd:
-    (CODEMETA_TERMS, NUGET_TABLE) = _read_crosstable(fd)
+    (CODEMETA_TERMS, NUGET_TABLE) = read_crosstable(fd)
 
 SPDX = URIRef("https://spdx.org/licenses/")