EmilStenstrom: Looks good, thanks! 🚀 
diff --git a/conllu/parser.py b/conllu/parser.py
index 16ec94b..7456879 100644
--- a/conllu/parser.py
+++ b/conllu/parser.py
@@ -141,7 +141,7 @@ def parse_id_value(value):
 
 
 ANY_ID = re.compile(ID_SINGLE.pattern + "|" + ID_RANGE.pattern + "|" + ID_DOT_ID.pattern)
-DEPS_RE = re.compile("(" + ANY_ID.pattern + r"):[a-z][a-z_-]*(\:[a-z][a-z_-]*)?")
+DEPS_RE = re.compile("(" + ANY_ID.pattern + r"):[a-zA-Z][a-zA-Z0-9_-]*(\:[a-zA-Z][a-zA-Z0-9_-]*)?")
 MULTI_DEPS_PATTERN = re.compile(r"{}(\|{})*".format(DEPS_RE.pattern, DEPS_RE.pattern))
 
 def parse_paired_list_value(value):

Column 'deps' is not being parsed most of the time
Given the following sentence:

```
Removed.
```

The code at `parser.py:152` looks like this:

```python
def parse_paired_list_value(value):
    if fullmatch(MULTI_DEPS_PATTERN, value):
        return [
            (part.split(":", 1)[1], parse_id_value(part.split(":")[0]))
            for part in value.split("|")
        ]

    return parse_nullable_value(value)
```

Is seems like the definition of `MULTI_DEPS_PATTERN` is not correct. Most `deps` values are returned as strings instead of a list of tuples, because the parsing fails. For example `'1:compound|6:ARG1|9:ARG1'` is considered bad, but according to [the specification](https://universaldependencies.org/format.html#syntactic-annotation) this should be alright. Actually the code for parsing inside of the if-statement works perfectly on this line. `'4:ARG1'` is also being considered flawed, but `'5:measure'` is being considered okay.
diff --git a/tests/test_parser.py b/tests/test_parser.py
index 0e13a77..2733b58 100644
--- a/tests/test_parser.py
+++ b/tests/test_parser.py
@@ -361,6 +361,14 @@ class TestParsePairedListValue(unittest.TestCase):
             parse_paired_list_value("5:conj:and|8.1:nsubj:pass|9:nsubj:xsubj"),
             [("conj:and", 5), ("nsubj:pass", (8, ".", 1)), ("nsubj:xsubj", 9)]
         )
+        self.assertEqual(
+            parse_paired_list_value("1:compound|6:ARG|9:ARG1|10:ARG2"),
+            [('compound', 1), ('ARG', 6), ('ARG1', 9), ('ARG2', 10)]
+        )
+        self.assertNotEqual(
+            parse_paired_list_value("1:compound|6:ARG|9:ARG1|10:2ARG"),
+            [('compound', 1), ('ARG', 6), ('ARG1', 9), ('2ARG', 10)]
+        )
 
     def test_parse_empty(self):
         testcases = [

pip install -e .
parse_log_pytest
pytest
tox pytest
3.6
pytest --no-header -rA --tb=line --color=no -p no:cacheprovider -W ignore::DeprecationWarning
attrs @ file:///opt/conda/conda-bld/attrs_1642510447205/work
certifi==2021.5.30
-e git+https://github.com/EmilStenstrom/conllu.git@6da39c07ccafc4c280f10eb51b12165472a609a9#egg=conllu
distlib==0.3.9
filelock==3.4.1
importlib-metadata==4.8.3
importlib-resources==5.4.0
iniconfig @ file:///home/linux1/recipes/ci/iniconfig_1610983019677/work
more-itertools @ file:///tmp/build/80754af9/more-itertools_1637733554872/work
packaging @ file:///tmp/build/80754af9/packaging_1637314298585/work
platformdirs==2.4.0
pluggy @ file:///tmp/build/80754af9/pluggy_1615976315926/work
py @ file:///opt/conda/conda-bld/py_1644396412707/work
pyparsing @ file:///tmp/build/80754af9/pyparsing_1635766073266/work
pytest==6.2.4
six==1.17.0
toml @ file:///tmp/build/80754af9/toml_1616166611790/work
tox==3.28.0
typing_extensions @ file:///opt/conda/conda-bld/typing_extensions_1647553014482/work
virtualenv==20.17.1
zipp @ file:///tmp/build/80754af9/zipp_1633618647012/work

name: conllu
channels:
  - defaults
  - https://repo.anaconda.com/pkgs/main
  - https://repo.anaconda.com/pkgs/r
  - conda-forge
dependencies:
  - _libgcc_mutex=0.1=main
  - _openmp_mutex=5.1=1_gnu
  - attrs=21.4.0=pyhd3eb1b0_0
  - ca-certificates=2025.2.25=h06a4308_0
  - certifi=2021.5.30=py36h06a4308_0
  - importlib_metadata=4.8.1=hd3eb1b0_0
  - iniconfig=1.1.1=pyhd3eb1b0_0
  - ld_impl_linux-64=2.40=h12ee557_0
  - libffi=3.3=he6710b0_2
  - libgcc-ng=11.2.0=h1234567_1
  - libgomp=11.2.0=h1234567_1
  - libstdcxx-ng=11.2.0=h1234567_1
  - more-itertools=8.12.0=pyhd3eb1b0_0
  - ncurses=6.4=h6a678d5_0
  - openssl=1.1.1w=h7f8727e_0
  - packaging=21.3=pyhd3eb1b0_0
  - pip=21.2.2=py36h06a4308_0
  - pluggy=0.13.1=py36h06a4308_0
  - py=1.11.0=pyhd3eb1b0_0
  - pyparsing=3.0.4=pyhd3eb1b0_0
  - pytest=6.2.4=py36h06a4308_2
  - python=3.6.13=h12debd9_1
  - readline=8.2=h5eee18b_0
  - setuptools=58.0.4=py36h06a4308_0
  - sqlite=3.45.3=h5eee18b_0
  - tk=8.6.14=h39e8969_0
  - toml=0.10.2=pyhd3eb1b0_0
  - typing_extensions=4.1.1=pyh06a4308_0
  - wheel=0.37.1=pyhd3eb1b0_0
  - xz=5.6.4=h5eee18b_1
  - zipp=3.6.0=pyhd3eb1b0_0
  - zlib=1.2.13=h5eee18b_1
  - pip:
      - distlib==0.3.9
      - filelock==3.4.1
      - importlib-metadata==4.8.3
      - importlib-resources==5.4.0
      - platformdirs==2.4.0
      - six==1.17.0
      - tox==3.28.0
      - virtualenv==20.17.1
prefix: /opt/conda/envs/conllu

tests/test_parser.py::TestParsePairedListValue::test_parse_paired_list
tests/test_parser.py::TestParseSentencesGenerator::test_empty tests/test_parser.py::TestParseSentencesGenerator::test_ends_without_newline tests/test_parser.py::TestParseSentencesGenerator::test_multiple_newlines tests/test_parser.py::TestParseSentencesGenerator::test_simple tests/test_parser.py::TestParseTokenAndMetadata::test_custom_field_parsers tests/test_parser.py::TestParseTokenAndMetadata::test_custom_fields tests/test_parser.py::TestParseTokenAndMetadata::test_default_field_parsers_when_undefined tests/test_parser.py::TestParseTokenAndMetadata::test_empty tests/test_parser.py::TestParseTokenAndMetadata::test_invalid_metadata tests/test_parser.py::TestParseTokenAndMetadata::test_newlines_in_sentence tests/test_parser.py::TestParseLine::test_empty tests/test_parser.py::TestParseLine::test_parse_line tests/test_parser.py::TestParseLine::test_parse_line_fewer_columns tests/test_parser.py::TestParseLine::test_parse_line_nullable_fields tests/test_parser.py::TestParseLine::test_parse_line_only_id_head tests/test_parser.py::TestParseLine::test_parse_line_two_spaces tests/test_parser.py::TestParseLine::test_parse_line_with_spaces tests/test_parser.py::TestParseLine::test_parse_line_without_spacing tests/test_parser.py::TestParseCommentLine::test_parse_comment_line tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_multiple_equals tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_optional_value tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_optional_value_no_space tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_without_equals tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_without_space tests/test_parser.py::TestParseCommentLine::test_parse_comment_line_without_square tests/test_parser.py::TestParseCommentLine::test_parse_spaces_before_square tests/test_parser.py::TestParseIntValue::test_parse_int_value tests/test_parser.py::TestParseIDValue::test_decimal tests/test_parser.py::TestParseIDValue::test_none tests/test_parser.py::TestParseIDValue::test_range tests/test_parser.py::TestParseIDValue::test_single tests/test_parser.py::TestParsePairedListValue::test_parse_empty tests/test_parser.py::TestParsePairedListValue::test_parse_invalid tests/test_parser.py::TestParseDictValue::test_parse_dict_value tests/test_parser.py::TestParseNullableValue::test_parse_nullable_value tests/test_parser.py::TestHeadToToken::test_decimal_ids_ignored tests/test_parser.py::TestHeadToToken::test_missing_head tests/test_parser.py::TestHeadToToken::test_negative_head tests/test_parser.py::TestHeadToToken::test_range_ids_ignored tests/test_parser.py::TestHeadToToken::test_simple tests/test_parser.py::TestSerializeField::test_list tests/test_parser.py::TestSerializeField::test_none tests/test_parser.py::TestSerializeField::test_ordered_dict tests/test_parser.py::TestSerializeField::test_string tests/test_parser.py::TestSerializeField::test_tuple tests/test_parser.py::TestSerialize::test_identity_unicode tests/test_parser.py::TestSerialize::test_metadata tests/test_parser.py::TestSerialize::test_serialize_tricky_fields
conllu/parser.py
conllu/parser.py