diff --git a/src/decaylanguage/data/decfile.lark b/src/decaylanguage/data/decfile.lark
index 1bb7746c..beeb467b 100644
--- a/src/decaylanguage/data/decfile.lark
+++ b/src/decaylanguage/data/decfile.lark
@@ -6,17 +6,17 @@
 start : _NEWLINE* (line _NEWLINE+)* ("End" _NEWLINE+)?
 ?line : define | particle_def | pythia_def | jetset_def | ls_def | model_alias | alias | chargeconj | commands | decay | cdecay | copydecay | setlspw | setlsbw | changemasslimit | inc_factor
 
-pythia_def : LABEL_PYTHIA_PARAMETERS LABEL ":" LABEL "=" (LABEL | SIGNED_NUMBER)
+pythia_def : LABEL_PYTHIA8_COMMANDS LABEL ":" LABEL "=" (LABEL | SIGNED_NUMBER)  // Pythia 8 commands
+LABEL_PYTHIA8_COMMANDS : "PythiaAliasParam" | "PythiaBothParam" | "PythiaGenericParam"
 
-LABEL_PYTHIA_PARAMETERS : "PythiaBothParam" | "PythiaAliasParam"
-
-jetset_def : "JetSetPar" LABEL "=" SIGNED_NUMBER
+jetset_def : "JetSetPar" LABEL "=" SIGNED_NUMBER  // Old Pythia 6 commands
 
 ls_def : LABEL_LINESHAPE LABEL // Choose a lineshape for a particle
+LABEL_LINESHAPE : "LSFLAT" | "LSNONRELBW" | "LSMANYDELTAFUNC" // Lineshape flat | non-relativistic BW, spikes
 
-LABEL_LINESHAPE : "LSFLAT" | "LSNONRELBW" | "LSMANYDELTAFUNC"
-
-inc_factor: ("IncludeBirthFactor" | "IncludeDecayFactor") label ("yes" | "no") // Presence of the birth/decay momentum factor and form-factor
+inc_factor: LABEL_INCLUDE_FACTOR LABEL BOOLEAN_INCLUDE_FACTOR // Presence of the birth/decay momentum factor and form-factor
+LABEL_INCLUDE_FACTOR : "IncludeBirthFactor" | "IncludeDecayFactor"
+BOOLEAN_INCLUDE_FACTOR : "yes" | "no"
 
 setlsbw : "BlattWeisskopf" LABEL SIGNED_NUMBER // Set Blatt-Weisskopf barrier factor for a lineshape
 
@@ -26,7 +26,7 @@ cdecay : "CDecay" LABEL
 
 define : "Define" LABEL SIGNED_NUMBER
 
-particle_def: "Particle" label value value // Set the mass and width of a particle (in GeV)
+particle_def: "Particle" LABEL SIGNED_NUMBER SIGNED_NUMBER // Set the mass and width of a particle (in GeV)
 
 model_alias : "ModelAlias" model_label model
 
@@ -35,7 +35,6 @@ alias : "Alias" LABEL LABEL
 chargeconj : "ChargeConj" LABEL LABEL
 
 changemasslimit : LABEL_CHANGE_MASS LABEL SIGNED_NUMBER // Set upper/lower mass cuts on a lineshape
-
 LABEL_CHANGE_MASS : "ChangeMassMin" | "ChangeMassMax"
 
 ?commands : global_photos
diff --git a/src/decaylanguage/dec/dec.py b/src/decaylanguage/dec/dec.py
index c1997d5b..bdd7a726 100644
--- a/src/decaylanguage/dec/dec.py
+++ b/src/decaylanguage/dec/dec.py
@@ -384,14 +384,16 @@ def get_particle_property_definitions(self) -> dict[str, dict[str, float]]:
 
     def dict_pythia_definitions(self) -> dict[str, dict[str, str | float]]:
         """
-        Return a dictionary of all Pythia definitions, with keys corresponding to the types
-        <PYTHIA_DEF> = "PythiaBothParam" and/or "PythiaAliasParam",
-        set in the input parsed file with statements of the form
-        "<PYTHIA_DEF> <NAME>=<LABEL>"
-        or
-        "<PYTHIA_DEF> <NAME>=<NUMBER>",
-        as {"PythiaAliasParam": {'NAME1': 'LABEL1', 'NAME2': VALUE2, ...},
-            "PythiaBothParam": {'NAME3': 'LABEL3', 'NAME4': VALUE4, ...}}.
+        Return a dictionary of all Pythia 8 commands
+        "PythiaGenericParam" and/or "PythiaAliasParam" and/or "PythiaBothParam",
+        with keys corresponding to the 3 types specifying whether the command is for
+        generic decays, alias decays, or both.
+        The commands are set in the input parsed file with statements of the form
+        "Pythia<TYPE>Param <MODULE>:<PARAM>=<LABEL_OR_VALUE>.
+        The dictionary takes the form
+        {"PythiaAliasParam": {'<MODULE1>:<PARAM1>': 'LABEL1', '<MODULE1>:<PARAM2>': VALUE2, ...},
+         "PythiaBothParam": {'<MODULE2>:<PARAM3>': 'LABEL3', '<MODULE3>:<PARAM4>': VALUE4, ...},
+         "PythiaGenericParam": {'<MODULE4>:<PARAM5>': 'LABEL5', '<MODULE5>:<PARAM6>': VALUE6, ...}}.
         """
         self._check_parsing()
         return get_pythia_definitions(self._parsed_dec_file)
@@ -400,10 +402,11 @@ def dict_jetset_definitions(self) -> dict[str, dict[int, int | float | str]]:
         """
         Return a dictionary of all JETSET definitions in the input parsed file,
         of the form
-        "JetSetPar <PARAM>(<PNUMBER>)=<NUMBER>"
-        as {'PARAM1': {PNUMBER1: VALUE1, PNUMBER2: VALUE2, ...},
-            'PARAM2': {...},
-            ...}.
+        "JetSetPar <MODULE>(<PARAMETER>)=<VALUE>"
+        as
+        {'MODULE1': {PARAMETER1: VALUE1, PARAMETER2: VALUE2, ...},
+         'MODULE2': {...},
+         ...}.
         """
         self._check_parsing()
         return get_jetset_definitions(self._parsed_dec_file)
@@ -430,7 +433,9 @@ def dict_lineshape_settings(self) -> dict[str, dict[str, str | float]]:
          PARTICLE2: {'lineshape': 'NAME2',
           'BlattWeisskopf': VALUE2,
           'ChangeMassMin': VALUE22,
-          'ChangeMassMax': VALUE23},
+          'ChangeMassMax': VALUE23,
+          'IncludeBirthFactor': TRUE_OR_FALSE,
+          'IncludeDecayFactor': TRUE_OR_FALSE},
          ...
         }
         where not all "sub-dictionaries" may contain all and/or the same keys.
@@ -1547,11 +1552,9 @@ def get_particle_property_definitions(parsed_file: Tree) -> dict[str, dict[str,
     """
     try:
         return {
-            tree.children[0]
-            .children[0]
-            .value: {
-                "mass": float(tree.children[1].children[0].value),
-                "width": float(tree.children[2].children[0].value),
+            tree.children[0].value: {
+                "mass": float(tree.children[1].value),
+                "width": float(tree.children[2].value),
             }
             for tree in parsed_file.find_data("particle_def")
         }
@@ -1563,14 +1566,16 @@ def get_particle_property_definitions(parsed_file: Tree) -> dict[str, dict[str,
 
 def get_pythia_definitions(parsed_file: Tree) -> dict[str, dict[str, str | float]]:
     """
-    Return a dictionary of all Pythia definitions, with keys corresponding to the types
-    <PYTHIA_DEF> = "PythiaBothParam" and/or "PythiaAliasParam",
-    set in the input parsed file with statements of the form
-    "<PYTHIA_DEF> <NAME>=<LABEL>"
-    or
-    "<PYTHIA_DEF> <NAME>=<NUMBER>",
-    as {"PythiaAliasParam": {'NAME1': 'LABEL1', 'NAME2': VALUE2, ...},
-        "PythiaBothParam": {'NAME3': 'LABEL3', 'NAME4': VALUE4, ...}}.
+    Return a dictionary of all Pythia 8 commands
+    "PythiaGenericParam" and/or "PythiaAliasParam" and/or "PythiaBothParam",
+    with keys corresponding to the 3 types specifying whether the command is for
+    generic decays, alias decays, or both.
+    The commands are set in the input parsed file with statements of the form
+    "Pythia<TYPE>Param <MODULE>:<PARAM>=<LABEL_OR_VALUE>.
+    The dictionary takes the form
+    {"PythiaAliasParam": {'<MODULE1>:<PARAM1>': 'LABEL1', '<MODULE1>:<PARAM2>': VALUE2, ...},
+     "PythiaBothParam": {'<MODULE2>:<PARAM3>': 'LABEL3', '<MODULE3>:<PARAM4>': VALUE4, ...},
+     "PythiaGenericParam": {'<MODULE4>:<PARAM5>': 'LABEL5', '<MODULE5>:<PARAM6>': VALUE6, ...}}.
 
     Parameters
     ----------
@@ -1608,10 +1613,11 @@ def get_jetset_definitions(
     """
     Return a dictionary of all JETSET definitions in the input parsed file,
     of the form
-    "JetSetPar <PARAM>(<PNUMBER>)=<NUMBER>"
-    as {'PARAM1': {PNUMBER1: VALUE1, PNUMBER2: VALUE2, ...},
-        'PARAM2': {...},
-        ...}.
+    "JetSetPar <MODULE>(<PARAMETER>)=<VALUE>"
+    as
+    {'MODULE1': {PARAMETER1: VALUE1, PARAMETER2: VALUE2, ...},
+     'MODULE2': {...},
+     ...}.
 
     Parameters
     ----------
@@ -1674,8 +1680,10 @@ def get_lineshape_settings(
       PARTICLE2: {'lineshape': 'NAME2',
        'BlattWeisskopf': VALUE21,
        'ChangeMassMin': VALUE22,
-       'ChangeMassMax': VALUE23},
-       ...
+       'ChangeMassMax': VALUE23,
+       'IncludeBirthFactor': TRUE_OR_FALSE,
+       'IncludeDecayFactor': TRUE_OR_FALSE},
+      ...
      }
      where not all "sub-dictionaries" may contain all and/or the same keys.
 
@@ -1723,6 +1731,22 @@ def get_lineshape_settings(
                     f"{tree.children[0].value}": float(tree.children[2].value)
                 }
 
+        # Presence of the birth/decay momentum factor and form-factor
+        for tree in parsed_file.find_data("inc_factor"):
+            particle_or_alias = tree.children[1].value
+            if particle_or_alias in d:
+                if tree.children[0].value in d[particle_or_alias]:
+                    raise RuntimeError(
+                        f"The birth/decay momentum factor for particle/alias {particle_or_alias} seems to be redefined."
+                    ) from None
+                d[particle_or_alias][f"{tree.children[0].value}"] = _str_to_bool(
+                    tree.children[2].value
+                )
+            else:
+                d[particle_or_alias] = {
+                    f"{tree.children[0].value}": _str_to_bool(tree.children[2].value)
+                }
+
         return d
 
     except Exception as err:
@@ -1796,3 +1820,14 @@ def _str_or_float(arg: str) -> str | float:
         return float(arg)
     except Exception:
         return arg
+
+
+def _str_to_bool(arg: str) -> bool:
+    if arg == "yes":
+        return True
+    if arg == "no":
+        return False
+
+    raise ValueError(
+        f"String {arg!r} cannot be converted to boolean! Only 'yes/no' accepted."
+    )
diff --git a/tests/data/defs-aliases-chargeconj.dec b/tests/data/defs-aliases-chargeconj.dec
index 61353b56..a5478a39 100644
--- a/tests/data/defs-aliases-chargeconj.dec
+++ b/tests/data/defs-aliases-chargeconj.dec
@@ -272,10 +272,18 @@ Alias MyKS0pipi K_10
 LSFLAT MyKS0pipi
 ChangeMassMin MyKS0pipi 1.1
 ChangeMassMax MyKS0pipi 2.4
+#
+Particle rho0 0.8 0.2
+ChangeMassMin rho0 0.7
+ChangeMassMax rho0 0.9
+LSNONRELBW rho0
+BlattWeisskopf rho0 3.0
+IncludeBirthFactor rho0 no
+IncludeDecayFactor rho0 yes
 
-#JetSet parameter modifications
-#(Very important that there are no blank spaces in the parameter string!)
-#Turn off B0-B0B mixing in Pythia
+# Pythia 8 parameter modifications
+# (Very important that there are no blank spaces in the parameter string!)
+# Turn off B0-B0B mixing in Pythia
 PythiaBothParam ParticleDecays:mixB=off
 PythiaBothParam Init:showChangedSettings=off
 PythiaBothParam Init:showChangedParticleData=off
@@ -284,6 +292,7 @@ PythiaBothParam Next:numberShowEvent=0
 PythiaAliasParam ParticleDecays:sophisticatedTau=3
 PythiaAliasParam ParticleDecays:tauPolarization=-1.
 
+# Old Pythia 6 parameter modifications
 JetSetPar MSTU(1)=0
 JetSetPar MSTU(2)=0
 JetSetPar PARU(11)=0.001
diff --git a/tests/dec/test_dec.py b/tests/dec/test_dec.py
index 21be1661..63f86dca 100644
--- a/tests/dec/test_dec.py
+++ b/tests/dec/test_dec.py
@@ -204,6 +204,7 @@ def test_particle_property_definitions():
     assert p.get_particle_property_definitions() == {
         "MyK*0": {"mass": 0.892, "width": 0.051},
         "MyPhi": {"mass": 1.02, "width": 0.004},
+        "rho0": {"mass": 0.8, "width": 0.2},
     }
 
 
@@ -259,6 +260,14 @@ def test_dict_lineshape_settings():
             "ChangeMassMin": 1.1,
             "ChangeMassMax": 2.4,
         },
+        "rho0": {
+            "lineshape": "LSNONRELBW",
+            "BlattWeisskopf": 3.0,
+            "ChangeMassMax": 0.9,
+            "ChangeMassMin": 0.7,
+            "IncludeBirthFactor": False,
+            "IncludeDecayFactor": True,
+        },
     }