diff --git a/nameparser/config/suffixes.py b/nameparser/config/suffixes.py
index ff9eb1e4..0cf723b3 100644
--- a/nameparser/config/suffixes.py
+++ b/nameparser/config/suffixes.py
@@ -326,12 +326,9 @@
     'acha',
     'acp',
     'ae',
-    'ae',
     'aem',
     'afasma',
     'afc',
-    'afc',
-    'afm',
     'afm',
     'agsf',
     'aia',
@@ -453,7 +450,6 @@
     'cgfm',
     'cgfo',
     'cgm',
-    'cgm',
     'cgma',
     'cgp',
     'cgr',
@@ -464,7 +460,6 @@
     'che',
     'ches',
     'chfc',
-    'chfc',
     'chi',
     'chmc',
     'chmm',
@@ -679,14 +674,11 @@
     'gbe',
     'gc',
     'gcb',
-    'gcb',
     'gchs',
     'gcie',
     'gcmg',
-    'gcmg',
     'gcsi',
     'gcvo',
-    'gcvo',
     'gisp',
     'git',
     'gm',
@@ -717,10 +709,8 @@
     'kcb',
     'kchs/dchs',
     'kcie',
-    'kcie',
     'kcmg',
     'kcsi',
-    'kcsi',
     'kcvo',
     'kg',
     'khs/dhs',
@@ -928,7 +918,6 @@
     'uxc',
     'uxmc',
     'vc',
-    'vc',
     'vcp',
     'vd',
     'vrd',
diff --git a/nameparser/config/titles.py b/nameparser/config/titles.py
index ce2b3349..c9ecec4d 100644
--- a/nameparser/config/titles.py
+++ b/nameparser/config/titles.py
@@ -494,7 +494,6 @@
     'marcher',
     'marchess',
     'marketing',
-    'marquis',
     'mathematician',
     'mathematics',
     'matriarch',
diff --git a/pyproject.toml b/pyproject.toml
index 9959e2a1..50710597 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -119,6 +119,7 @@ filterwarnings = [
 extend-select = [
   "ANN",   # flake8-annotations
   "UP",    # pyupgrade
+  "B033",  # duplicate set items: a frozenset drops them silently, so a bulk vocabulary import can carry them unseen
 ]
 ignore = [
   "E74",     # ambiguous-{variable,class,function}-name (I have trouble believing that these are real rules)