diff --git a/src/mo_frontend/typing.ml b/src/mo_frontend/typing.ml
index cc818699b33..9710a15af50 100644
--- a/src/mo_frontend/typing.ml
+++ b/src/mo_frontend/typing.ml
@@ -1509,13 +1509,13 @@ and infer_exp'' env exp : T.typ =
     t
   | SwitchE (exp1, cases) ->
     let t1 = infer_exp_promote env exp1 in
-    let t = infer_cases env t1 T.Non cases in
+    let t = infer_cases env true t1 T.Non cases in
     if not env.pre then
       coverage_cases "switch" env cases t1 exp.at;
     t
   | TryE (exp1, cases) ->
     let t1 = infer_exp env exp1 in
-    let t2 = infer_cases env T.catch T.Non cases in
+    let t2 = infer_cases env false T.catch T.Non cases in
     if not env.pre then begin
       check_ErrorCap env "try" exp.at;
       coverage_cases "try handler" env cases T.catch exp.at
@@ -1975,15 +1975,17 @@ and infer_call env exp1 inst exp2 at t_expect_opt =
 
 (* Cases *)
 
-and infer_cases env t_pat t cases : T.typ =
-  List.fold_left (infer_case env t_pat) t cases
+and infer_cases env check_unused t_pat t cases : T.typ =
+  List.fold_left (infer_case env check_unused t_pat) t cases
 
-and infer_case env t_pat t case =
+and infer_case env check_unused t_pat t case =
   let {pat; exp} = case.it in
   let ve = check_pat env t_pat pat in
   let initial_usage = enter_scope env in
   let t' = recover_with T.Non (infer_exp (adjoin_vals env ve)) exp in
-  leave_scope env ve initial_usage;
+  if check_unused then
+    leave_scope env ve initial_usage
+  else ();
   let t'' = T.lub t t' in
   if not env.pre && inconsistent t'' [t; t'] then
     warn env case.at "M0101"
@@ -1998,8 +2000,11 @@ and check_cases env t_pat t cases =
 
 and check_case env t_pat t case =
   let {pat; exp} = case.it in
+  let initial_usage = enter_scope env in
   let ve = check_pat env t_pat pat in
-  recover (check_exp (adjoin_vals env ve) t) exp
+  let t' = recover (check_exp (adjoin_vals env ve) t) exp in
+  leave_scope env ve initial_usage;
+  t'
 
 and inconsistent t ts =
   T.opaque t && not (List.exists T.opaque ts)
diff --git a/test/fail/ok/actor-match.tc.ok b/test/fail/ok/actor-match.tc.ok
index daf0d34053c..4653d0dbb32 100644
--- a/test/fail/ok/actor-match.tc.ok
+++ b/test/fail/ok/actor-match.tc.ok
@@ -1,2 +1,4 @@
 actor-match.mo:7.8-7.14: type error [M0114], object pattern cannot consume actor type
   actor {f : shared () -> (); g : shared () -> ()}
+actor-match.mo:7.9-7.10: warning [M0198], unused field f in object pattern (delete or rewrite as `f = _`)
+actor-match.mo:7.12-7.13: warning [M0198], unused field g in object pattern (delete or rewrite as `g = _`)
diff --git a/test/fail/ok/unused.tc.ok b/test/fail/ok/unused.tc.ok
index 183c85edb82..80df6352cc8 100644
--- a/test/fail/ok/unused.tc.ok
+++ b/test/fail/ok/unused.tc.ok
@@ -5,5 +5,7 @@ unused.mo:9.9-9.15: warning [M0194], unused identifier unused (delete or rename
 unused.mo:11.6-11.7: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
 unused.mo:11.8-11.9: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
 unused.mo:15.5-15.8: warning [M0194], unused identifier hmm (delete or rename to wildcard `_` or `_hmm`)
+unused.mo:23.10-23.11: warning [M0194], unused identifier u (delete or rename to wildcard `_` or `_u`)
+unused.mo:24.8-24.9: warning [M0194], unused identifier o (delete or rename to wildcard `_` or `_o`)
 unused.mo:32.5-32.6: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 unused.mo:32.29-32.30: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
diff --git a/test/perf/ok/assetstorage.tc.ok b/test/perf/ok/assetstorage.tc.ok
index 64a6076d547..de9f3224a19 100644
--- a/test/perf/ok/assetstorage.tc.ok
+++ b/test/perf/ok/assetstorage.tc.ok
@@ -1,5 +1,10 @@
+assetstorage/List.mo:66.19-66.20: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+assetstorage/List.mo:201.16-201.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 assetstorage/Iter.mo:165.29-165.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)
 assetstorage/RBTree.mo:45.10-45.13: warning [M0194], unused identifier res (delete or rename to wildcard `_` or `_res`)
 assetstorage/RBTree.mo:50.10-50.13: warning [M0194], unused identifier res (delete or rename to wildcard `_` or `_res`)
+assetstorage/RBTree.mo:179.15-179.16: warning [M0194], unused identifier c (delete or rename to wildcard `_` or `_c`)
 assetstorage/Char.mo:8.15-8.22: warning [M0194], unused identifier toUpper (delete or rename to wildcard `_` or `_toUpper`)
 assetstorage/Char.mo:11.15-11.22: warning [M0194], unused identifier toLower (delete or rename to wildcard `_` or `_toLower`)
+assetstorage/Text.mo:347.22-347.25: warning [M0194], unused identifier cs1 (delete or rename to wildcard `_` or `_cs1`)
+assetstorage/Text.mo:548.28-548.31: warning [M0194], unused identifier cs3 (delete or rename to wildcard `_` or `_cs3`)
diff --git a/test/perf/ok/dao.tc.ok b/test/perf/ok/dao.tc.ok
index 933cc821311..5dd3cddfb74 100644
--- a/test/perf/ok/dao.tc.ok
+++ b/test/perf/ok/dao.tc.ok
@@ -1,4 +1,8 @@
+assetstorage/List.mo:66.19-66.20: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+assetstorage/List.mo:201.16-201.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 assetstorage/Iter.mo:165.29-165.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)
+assetstorage/AssocList.mo:158.20-158.22: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
+assetstorage/AssocList.mo:313.20-313.22: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
 assetstorage/Trie.mo:206.31-206.32: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
 assetstorage/Trie.mo:486.25-486.26: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
 assetstorage/Trie.mo:588.9-588.15: warning [M0194], unused identifier key_eq (delete or rename to wildcard `_` or `_key_eq`)
diff --git a/test/perf/ok/qr.tc.ok b/test/perf/ok/qr.tc.ok
index bd2bd86a236..f74e9439d34 100644
--- a/test/perf/ok/qr.tc.ok
+++ b/test/perf/ok/qr.tc.ok
@@ -1,5 +1,9 @@
 qr/option.mo:52.8-52.11: warning [M0194], unused identifier map (delete or rename to wildcard `_` or `_map`)
+qr/list.mo:124.21-124.22: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+qr/list.mo:281.18-281.19: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 qr/iter.mo:36.8-36.14: warning [M0194], unused identifier length (delete or rename to wildcard `_` or `_length`)
+qr/assocList.mo:105.25-105.27: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
+qr/assocList.mo:179.25-179.27: warning [M0194], unused identifier v2 (delete or rename to wildcard `_` or `_v2`)
 qr/trie.mo:515.9-515.15: warning [M0194], unused identifier key_eq (delete or rename to wildcard `_` or `_key_eq`)
 qr/trie.mo:893.7-893.12: warning [M0194], unused identifier k3_eq (delete or rename to wildcard `_` or `_k3_eq`)
 qr/trie.mo:1447.61-1447.66: warning [M0194], unused identifier k1_eq (delete or rename to wildcard `_` or `_k1_eq`)
diff --git a/test/perf/ok/sha256.tc.ok b/test/perf/ok/sha256.tc.ok
index d1c7d20a1ed..d129613d95c 100644
--- a/test/perf/ok/sha256.tc.ok
+++ b/test/perf/ok/sha256.tc.ok
@@ -1 +1,3 @@
+sha256/List.mo:67.22-67.23: warning [M0194], unused identifier t (delete or rename to wildcard `_` or `_t`)
+sha256/List.mo:204.16-204.17: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
 sha256/Iter.mo:194.29-194.31: warning [M0194], unused identifier ix (delete or rename to wildcard `_` or `_ix`)
diff --git a/test/run-drun/ok/actor-class-mgmt-interp.tc.ok b/test/run-drun/ok/actor-class-mgmt-interp.tc.ok
new file mode 100644
index 00000000000..018308bd8d0
--- /dev/null
+++ b/test/run-drun/ok/actor-class-mgmt-interp.tc.ok
@@ -0,0 +1,4 @@
+actor-class-mgmt-interp.mo:37.15-37.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:46.15-46.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:54.15-54.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+actor-class-mgmt-interp.mo:63.13-63.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/composite-inspect-message.tc.ok b/test/run-drun/ok/composite-inspect-message.tc.ok
index 58ee9d7bde2..6d056d1d66a 100644
--- a/test/run-drun/ok/composite-inspect-message.tc.ok
+++ b/test/run-drun/ok/composite-inspect-message.tc.ok
@@ -1 +1,2 @@
 composite-inspect-message.mo:17.8-17.14: warning [M0194], unused identifier caller (delete or rename to wildcard `_` or `_caller`)
+composite-inspect-message.mo:29.20-29.21: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
diff --git a/test/run-drun/ok/error-codes.tc.ok b/test/run-drun/ok/error-codes.tc.ok
index 85ed2afe24b..3d8b5261242 100644
--- a/test/run-drun/ok/error-codes.tc.ok
+++ b/test/run-drun/ok/error-codes.tc.ok
@@ -1 +1,3 @@
 error-codes.mo:8.16-8.23: warning [M0194], unused identifier invalid (delete or rename to wildcard `_` or `_invalid`)
+error-codes.mo:47.24-47.25: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+error-codes.mo:48.28-48.36: warning [M0194], unused identifier err_code (delete or rename to wildcard `_` or `_err_code`)
diff --git a/test/run-drun/ok/from_candid_trap.tc.ok b/test/run-drun/ok/from_candid_trap.tc.ok
new file mode 100644
index 00000000000..a4f6f3dd0df
--- /dev/null
+++ b/test/run-drun/ok/from_candid_trap.tc.ok
@@ -0,0 +1 @@
+from_candid_trap.mo:11.13-11.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/gc-trigger-acl.tc.ok b/test/run-drun/ok/gc-trigger-acl.tc.ok
new file mode 100644
index 00000000000..2e4af877257
--- /dev/null
+++ b/test/run-drun/ok/gc-trigger-acl.tc.ok
@@ -0,0 +1,2 @@
+gc-trigger-acl.mo:25.13-25.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+gc-trigger-acl.mo:38.13-38.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/idl-record.tc.ok b/test/run-drun/ok/idl-record.tc.ok
new file mode 100644
index 00000000000..75c07fc97c1
--- /dev/null
+++ b/test/run-drun/ok/idl-record.tc.ok
@@ -0,0 +1 @@
+idl-record.mo:8.14-8.21: warning [M0194], unused identifier content (delete or rename to wildcard `_` or `_content`)
diff --git a/test/run-drun/ok/idl-sub-ho-neg.tc.ok b/test/run-drun/ok/idl-sub-ho-neg.tc.ok
index 8d0b32579e8..3ba4eac5684 100644
--- a/test/run-drun/ok/idl-sub-ho-neg.tc.ok
+++ b/test/run-drun/ok/idl-sub-ho-neg.tc.ok
@@ -48,3 +48,22 @@ idl-sub-ho-neg.mo:103.28-103.29: warning [M0194], unused identifier n (delete or
 idl-sub-ho-neg.mo:103.41-103.42: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-ho-neg.mo:103.56-103.57: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 idl-sub-ho-neg.mo:103.75-103.76: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+idl-sub-ho-neg.mo:131.15-131.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:145.15-145.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:159.15-159.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:173.15-173.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:187.15-187.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:201.15-201.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:215.15-215.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:232.15-232.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:248.15-248.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:264.15-264.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:279.15-279.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:296.15-296.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:313.15-313.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:330.15-330.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:346.15-346.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:362.15-362.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:377.15-377.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:394.15-394.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho-neg.mo:411.15-411.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/idl-sub-ho.tc.ok b/test/run-drun/ok/idl-sub-ho.tc.ok
index c996dff24fa..948d94f030b 100644
--- a/test/run-drun/ok/idl-sub-ho.tc.ok
+++ b/test/run-drun/ok/idl-sub-ho.tc.ok
@@ -26,3 +26,14 @@ idl-sub-ho.mo:78.26-78.27: warning [M0194], unused identifier n (delete or renam
 idl-sub-ho.mo:78.39-78.40: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-ho.mo:78.54-78.55: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 idl-sub-ho.mo:78.73-78.74: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+idl-sub-ho.mo:100.15-100.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:111.15-111.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:122.15-122.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:133.15-133.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:145.15-145.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:159.15-159.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:173.15-173.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:188.15-188.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:203.15-203.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:217.15-217.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-ho.mo:232.15-232.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/idl-sub-opt-any-record.tc.ok b/test/run-drun/ok/idl-sub-opt-any-record.tc.ok
index b093e3fbd96..2116494167a 100644
--- a/test/run-drun/ok/idl-sub-opt-any-record.tc.ok
+++ b/test/run-drun/ok/idl-sub-opt-any-record.tc.ok
@@ -5,3 +5,6 @@ idl-sub-opt-any-record.mo:15.24-15.25: warning [M0194], unused identifier a (del
 idl-sub-opt-any-record.mo:15.33-15.34: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
 idl-sub-opt-any-record.mo:16.24-16.25: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-opt-any-record.mo:16.33-16.34: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+idl-sub-opt-any-record.mo:31.15-31.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any-record.mo:46.15-46.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any-record.mo:60.15-60.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/idl-sub-opt-any.tc.ok b/test/run-drun/ok/idl-sub-opt-any.tc.ok
index a070db4853e..3090b41d84b 100644
--- a/test/run-drun/ok/idl-sub-opt-any.tc.ok
+++ b/test/run-drun/ok/idl-sub-opt-any.tc.ok
@@ -9,3 +9,8 @@ idl-sub-opt-any.mo:17.23-17.24: warning [M0194], unused identifier n (delete or
 idl-sub-opt-any.mo:17.34-17.35: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-opt-any.mo:18.23-18.24: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
 idl-sub-opt-any.mo:18.32-18.33: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
+idl-sub-opt-any.mo:33.15-33.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:48.15-48.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:62.15-62.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:76.15-76.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-opt-any.mo:91.15-91.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/idl-sub-rec.tc.ok b/test/run-drun/ok/idl-sub-rec.tc.ok
index 6876891bf8d..428c25b6584 100644
--- a/test/run-drun/ok/idl-sub-rec.tc.ok
+++ b/test/run-drun/ok/idl-sub-rec.tc.ok
@@ -7,3 +7,11 @@ idl-sub-rec.mo:54.5-54.6: warning [M0194], unused identifier a (delete or rename
 idl-sub-rec.mo:60.5-60.6: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
 idl-sub-rec.mo:66.5-66.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
 idl-sub-rec.mo:72.5-72.6: warning [M0194], unused identifier a (delete or rename to wildcard `_` or `_a`)
+idl-sub-rec.mo:91.13-91.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:104.13-104.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:118.13-118.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:131.13-131.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:144.13-144.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:169.13-169.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:181.13-181.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+idl-sub-rec.mo:194.13-194.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/inspect_message.tc.ok b/test/run-drun/ok/inspect_message.tc.ok
index 4346feb3e7e..29eadd89c7f 100644
--- a/test/run-drun/ok/inspect_message.tc.ok
+++ b/test/run-drun/ok/inspect_message.tc.ok
@@ -1 +1,2 @@
 inspect_message.mo:14.8-14.14: warning [M0194], unused identifier caller (delete or rename to wildcard `_` or `_caller`)
+inspect_message.mo:26.20-26.21: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
diff --git a/test/run-drun/ok/issue-3910.tc.ok b/test/run-drun/ok/issue-3910.tc.ok
index e0d3757ed0b..ad9eea9a3cf 100644
--- a/test/run-drun/ok/issue-3910.tc.ok
+++ b/test/run-drun/ok/issue-3910.tc.ok
@@ -10,3 +10,5 @@ issue-3910.mo:7.11-7.12: warning [M0194], unused identifier r (delete or rename
 issue-3910.mo:12.13-12.17: warning [M0194], unused identifier trap (delete or rename to wildcard `_` or `_trap`)
 issue-3910.mo:24.11-24.12: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
 issue-3910.mo:29.13-29.17: warning [M0194], unused identifier trap (delete or rename to wildcard `_` or `_trap`)
+issue-3910.mo:52.11-52.12: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+issue-3910.mo:67.11-67.12: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/local-throw.tc.ok b/test/run-drun/ok/local-throw.tc.ok
new file mode 100644
index 00000000000..a5b13a2b913
--- /dev/null
+++ b/test/run-drun/ok/local-throw.tc.ok
@@ -0,0 +1,3 @@
+local-throw.mo:14.19-14.22: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
+local-throw.mo:32.17-32.20: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
+local-throw.mo:45.14-45.17: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
diff --git a/test/run-drun/ok/neg-powers.tc.ok b/test/run-drun/ok/neg-powers.tc.ok
new file mode 100644
index 00000000000..3b1ee933887
--- /dev/null
+++ b/test/run-drun/ok/neg-powers.tc.ok
@@ -0,0 +1,36 @@
+neg-powers.mo:11.14-11.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:17.14-17.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:23.14-23.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:29.14-29.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:36.14-36.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:42.14-42.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:48.14-48.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:54.14-54.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:61.14-61.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:67.14-67.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:73.14-73.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:79.14-79.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:86.14-86.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:92.14-92.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:98.14-98.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:104.14-104.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:111.14-111.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:117.14-117.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:123.14-123.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:129.14-129.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:136.14-136.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:142.14-142.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:148.14-148.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:154.14-154.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:161.14-161.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:167.14-167.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:173.14-173.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:179.14-179.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:186.14-186.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:192.14-192.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:198.14-198.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:204.14-204.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:211.14-211.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:217.14-217.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:223.14-223.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+neg-powers.mo:229.14-229.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/oneway.tc.ok b/test/run-drun/ok/oneway.tc.ok
new file mode 100644
index 00000000000..f45d020d701
--- /dev/null
+++ b/test/run-drun/ok/oneway.tc.ok
@@ -0,0 +1,2 @@
+oneway.mo:13.11-13.12: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+oneway.mo:27.15-27.16: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/overflow.tc.ok b/test/run-drun/ok/overflow.tc.ok
new file mode 100644
index 00000000000..7315ebd336b
--- /dev/null
+++ b/test/run-drun/ok/overflow.tc.ok
@@ -0,0 +1,10 @@
+overflow.mo:11.14-11.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:17.14-17.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:23.14-23.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:29.14-29.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:35.14-35.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:41.14-41.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:47.14-47.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:53.14-53.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:59.14-59.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
+overflow.mo:65.14-65.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/region0-overflow.tc.ok b/test/run-drun/ok/region0-overflow.tc.ok
new file mode 100644
index 00000000000..1bfc2a83fa2
--- /dev/null
+++ b/test/run-drun/ok/region0-overflow.tc.ok
@@ -0,0 +1 @@
+region0-overflow.mo:58.13-58.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/reject.tc.ok b/test/run-drun/ok/reject.tc.ok
new file mode 100644
index 00000000000..438e7219e5c
--- /dev/null
+++ b/test/run-drun/ok/reject.tc.ok
@@ -0,0 +1 @@
+reject.mo:12.12-12.13: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/send-failure-example-trap.tc.ok b/test/run-drun/ok/send-failure-example-trap.tc.ok
new file mode 100644
index 00000000000..107a18c5c3c
--- /dev/null
+++ b/test/run-drun/ok/send-failure-example-trap.tc.ok
@@ -0,0 +1 @@
+send-failure-example-trap.mo:22.14-22.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/send-failure-example.tc.ok b/test/run-drun/ok/send-failure-example.tc.ok
new file mode 100644
index 00000000000..70987d25254
--- /dev/null
+++ b/test/run-drun/ok/send-failure-example.tc.ok
@@ -0,0 +1 @@
+send-failure-example.mo:21.14-21.15: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/stable-overflow.tc.ok b/test/run-drun/ok/stable-overflow.tc.ok
new file mode 100644
index 00000000000..941d5d4221c
--- /dev/null
+++ b/test/run-drun/ok/stable-overflow.tc.ok
@@ -0,0 +1 @@
+stable-overflow.mo:57.13-57.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/throw.tc.ok b/test/run-drun/ok/throw.tc.ok
index 4f8e30d6174..76054d5c934 100644
--- a/test/run-drun/ok/throw.tc.ok
+++ b/test/run-drun/ok/throw.tc.ok
@@ -1 +1,3 @@
+throw.mo:16.19-16.22: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
 throw.mo:38.19-38.22: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
+throw.mo:52.14-52.17: warning [M0194], unused identifier sys (delete or rename to wildcard `_` or `_sys`)
diff --git a/test/run-drun/ok/trap-on-async-failure.tc.ok b/test/run-drun/ok/trap-on-async-failure.tc.ok
new file mode 100644
index 00000000000..776f37cfb6b
--- /dev/null
+++ b/test/run-drun/ok/trap-on-async-failure.tc.ok
@@ -0,0 +1 @@
+trap-on-async-failure.mo:36.13-36.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/trap-on-send-failure.tc.ok b/test/run-drun/ok/trap-on-send-failure.tc.ok
new file mode 100644
index 00000000000..75b610fc5f8
--- /dev/null
+++ b/test/run-drun/ok/trap-on-send-failure.tc.ok
@@ -0,0 +1 @@
+trap-on-send-failure.mo:33.13-33.14: warning [M0194], unused identifier e (delete or rename to wildcard `_` or `_e`)
diff --git a/test/run-drun/ok/unused-exception.drun-run.ok b/test/run-drun/ok/unused-exception.drun-run.ok
new file mode 100644
index 00000000000..a6f776f43c6
--- /dev/null
+++ b/test/run-drun/ok/unused-exception.drun-run.ok
@@ -0,0 +1,2 @@
+ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
+ingress Completed: Reply: 0x4449444c0000
diff --git a/test/run-drun/ok/unused-exception.tc.ok b/test/run-drun/ok/unused-exception.tc.ok
new file mode 100644
index 00000000000..ea3d56553ff
--- /dev/null
+++ b/test/run-drun/ok/unused-exception.tc.ok
@@ -0,0 +1 @@
+unused-exception.mo:3.24-3.33: warning [M0194], unused identifier exception (delete or rename to wildcard `_` or `_exception`)
diff --git a/test/run-drun/ok/unused-switch-in-catch.drun-run.ok b/test/run-drun/ok/unused-switch-in-catch.drun-run.ok
new file mode 100644
index 00000000000..a6f776f43c6
--- /dev/null
+++ b/test/run-drun/ok/unused-switch-in-catch.drun-run.ok
@@ -0,0 +1,2 @@
+ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
+ingress Completed: Reply: 0x4449444c0000
diff --git a/test/run-drun/ok/unused-switch-in-catch.tc.ok b/test/run-drun/ok/unused-switch-in-catch.tc.ok
new file mode 100644
index 00000000000..a78dcca1876
--- /dev/null
+++ b/test/run-drun/ok/unused-switch-in-catch.tc.ok
@@ -0,0 +1 @@
+unused-switch-in-catch.mo:5.22-5.28: warning [M0194], unused identifier unused (delete or rename to wildcard `_` or `_unused`)
diff --git a/test/run-drun/ok/used-exception.drun-run.ok b/test/run-drun/ok/used-exception.drun-run.ok
new file mode 100644
index 00000000000..a6f776f43c6
--- /dev/null
+++ b/test/run-drun/ok/used-exception.drun-run.ok
@@ -0,0 +1,2 @@
+ingress Completed: Reply: 0x4449444c016c01b3c4b1f204680100010a00000000000000000101
+ingress Completed: Reply: 0x4449444c0000
diff --git a/test/run-drun/unused-exception.mo b/test/run-drun/unused-exception.mo
new file mode 100644
index 00000000000..d4c993c536b
--- /dev/null
+++ b/test/run-drun/unused-exception.mo
@@ -0,0 +1,5 @@
+module {
+    public func foo() : async () {
+        try { } catch (exception) {};
+    };
+};
diff --git a/test/run-drun/unused-switch-in-catch.mo b/test/run-drun/unused-switch-in-catch.mo
new file mode 100644
index 00000000000..4e1643c68e4
--- /dev/null
+++ b/test/run-drun/unused-switch-in-catch.mo
@@ -0,0 +1,11 @@
+module {
+    public func test() : async () {
+        try {} catch exception {
+            switch exception {
+                case unused {
+                    assert false;
+                };
+            };
+        };
+    };
+};
diff --git a/test/run-drun/used-exception.mo b/test/run-drun/used-exception.mo
new file mode 100644
index 00000000000..76092fd5bb1
--- /dev/null
+++ b/test/run-drun/used-exception.mo
@@ -0,0 +1,8 @@
+module {
+    public func foo() : async () {
+        var x = try {} catch (exception) {
+            throw exception;
+        };
+        x;
+    };
+};
diff --git a/test/run/ok/blobs.tc.ok b/test/run/ok/blobs.tc.ok
new file mode 100644
index 00000000000..6cdda86de42
--- /dev/null
+++ b/test/run/ok/blobs.tc.ok
@@ -0,0 +1 @@
+blobs.mo:38.10-38.11: warning [M0194], unused identifier b (delete or rename to wildcard `_` or `_b`)
diff --git a/test/run/ok/coverage.tc.ok b/test/run/ok/coverage.tc.ok
index 171ba1f9a4c..82405995a0d 100644
--- a/test/run/ok/coverage.tc.ok
+++ b/test/run/ok/coverage.tc.ok
@@ -195,4 +195,43 @@ coverage.mo:15.8-15.10: warning [M0194], unused identifier f3 (delete or rename
 coverage.mo:17.8-17.10: warning [M0194], unused identifier f5 (delete or rename to wildcard `_` or `_f5`)
 coverage.mo:18.8-18.10: warning [M0194], unused identifier f6 (delete or rename to wildcard `_` or `_f6`)
 coverage.mo:19.8-19.10: warning [M0194], unused identifier f7 (delete or rename to wildcard `_` or `_f7`)
+coverage.mo:22.19-22.20: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:26.30-26.31: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:28.30-28.31: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:29.19-29.20: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:30.19-30.20: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:30.30-30.31: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:100.13-100.14: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:101.14-101.15: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:101.21-101.22: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:102.14-102.15: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:102.22-102.23: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:102.25-102.26: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:103.14-103.15: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:103.22-103.23: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:103.25-103.26: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:104.19-104.20: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:104.22-104.23: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:104.26-104.27: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:105.19-105.20: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:105.22-105.23: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:105.26-105.27: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:106.13-106.14: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:106.20-106.21: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:106.23-106.24: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:106.26-106.27: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+coverage.mo:106.30-106.31: warning [M0194], unused identifier w (delete or rename to wildcard `_` or `_w`)
+coverage.mo:107.14-107.15: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:107.21-107.22: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:107.24-107.25: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:107.27-107.28: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+coverage.mo:108.13-108.14: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:108.16-108.17: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:108.24-108.25: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:108.27-108.28: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+coverage.mo:109.24-109.25: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+coverage.mo:109.32-109.33: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+coverage.mo:109.35-109.36: warning [M0194], unused identifier z (delete or rename to wildcard `_` or `_z`)
+coverage.mo:109.40-109.41: warning [M0194], unused identifier v (delete or rename to wildcard `_` or `_v`)
+coverage.mo:109.44-109.45: warning [M0194], unused identifier w (delete or rename to wildcard `_` or `_w`)
 coverage.mo:178.6-178.7: warning [M0194], unused identifier h (delete or rename to wildcard `_` or `_h`)
diff --git a/test/run/ok/pat-subtyping.tc.ok b/test/run/ok/pat-subtyping.tc.ok
index 8dd72107e2a..ee6436c0bd3 100644
--- a/test/run/ok/pat-subtyping.tc.ok
+++ b/test/run/ok/pat-subtyping.tc.ok
@@ -39,3 +39,29 @@ pat-subtyping.mo:212.8-212.10: warning [M0146], this pattern is never matched
 pat-subtyping.mo:213.8-213.10: warning [M0146], this pattern is never matched
 pat-subtyping.mo:214.8-214.12: warning [M0146], this pattern is never matched
 pat-subtyping.mo:215.8-215.12: warning [M0146], this pattern is never matched
+pat-subtyping.mo:15.9-15.10: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+pat-subtyping.mo:18.10-18.11: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+pat-subtyping.mo:29.9-29.10: warning [M0194], unused identifier p (delete or rename to wildcard `_` or `_p`)
+pat-subtyping.mo:32.10-32.11: warning [M0194], unused identifier p (delete or rename to wildcard `_` or `_p`)
+pat-subtyping.mo:35.10-35.11: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+pat-subtyping.mo:35.13-35.14: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+pat-subtyping.mo:38.11-38.12: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+pat-subtyping.mo:38.14-38.15: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+pat-subtyping.mo:41.9-41.10: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+pat-subtyping.mo:41.18-41.19: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+pat-subtyping.mo:44.10-44.11: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
+pat-subtyping.mo:44.19-44.20: warning [M0194], unused identifier y (delete or rename to wildcard `_` or `_y`)
+pat-subtyping.mo:62.9-62.10: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:65.10-65.11: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:68.10-68.11: warning [M0198], unused field a in object pattern (delete or rewrite as `a = _`)
+pat-subtyping.mo:68.13-68.14: warning [M0198], unused field b in object pattern (delete or rewrite as `b = _`)
+pat-subtyping.mo:71.11-71.12: warning [M0198], unused field a in object pattern (delete or rewrite as `a = _`)
+pat-subtyping.mo:71.14-71.15: warning [M0198], unused field b in object pattern (delete or rewrite as `b = _`)
+pat-subtyping.mo:94.9-94.10: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:97.10-97.11: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:100.10-100.11: warning [M0198], unused field a in object pattern (delete or rewrite as `a = _`)
+pat-subtyping.mo:103.11-103.12: warning [M0198], unused field a in object pattern (delete or rewrite as `a = _`)
+pat-subtyping.mo:106.9-106.10: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:109.10-109.11: warning [M0194], unused identifier r (delete or rename to wildcard `_` or `_r`)
+pat-subtyping.mo:133.10-133.11: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
+pat-subtyping.mo:137.11-137.12: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
diff --git a/test/run/ok/switch.tc.ok b/test/run/ok/switch.tc.ok
index 2eb9546c271..59cd87839ac 100644
--- a/test/run/ok/switch.tc.ok
+++ b/test/run/ok/switch.tc.ok
@@ -17,6 +17,7 @@ switch.mo:97.11-99.2: warning [M0145], this switch of type
   ?Nat
 does not cover value
   ?(_)
+switch.mo:31.8-31.9: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
 switch.mo:80.6-80.7: warning [M0194], unused identifier f (delete or rename to wildcard `_` or `_f`)
 switch.mo:90.6-90.7: warning [M0194], unused identifier g (delete or rename to wildcard `_` or `_g`)
 switch.mo:93.10-93.11: warning [M0194], unused identifier n (delete or rename to wildcard `_` or `_n`)
diff --git a/test/run/ok/unused-parameter.tc.ok b/test/run/ok/unused-parameter.tc.ok
new file mode 100644
index 00000000000..08dce6b93b8
--- /dev/null
+++ b/test/run/ok/unused-parameter.tc.ok
@@ -0,0 +1,2 @@
+unused-parameter.mo:1.6-1.10: warning [M0194], unused identifier test (delete or rename to wildcard `_` or `_test`)
+unused-parameter.mo:1.11-1.16: warning [M0194], unused identifier param (delete or rename to wildcard `_` or `_param`)
diff --git a/test/run/unused-parameter.mo b/test/run/unused-parameter.mo
new file mode 100644
index 00000000000..9bf4557d53c
--- /dev/null
+++ b/test/run/unused-parameter.mo
@@ -0,0 +1,3 @@
+func test(param:Int) {};
+
+let _ = switch (42,) { case (param) param};
diff --git a/test/viper/ok/private.tc.ok b/test/viper/ok/private.tc.ok
new file mode 100644
index 00000000000..8ff67ecd9de
--- /dev/null
+++ b/test/viper/ok/private.tc.ok
@@ -0,0 +1 @@
+private.mo:11.16-11.22: warning [M0194], unused identifier reward (delete or rename to wildcard `_` or `_reward`)
diff --git a/test/viper/ok/private.vpr.ok b/test/viper/ok/private.vpr.ok
index b483933b615..52f912acb39 100644
--- a/test/viper/ok/private.vpr.ok
+++ b/test/viper/ok/private.vpr.ok
@@ -1,3 +1,4 @@
+private.mo:11.16-11.22: warning [M0194], unused identifier reward (delete or rename to wildcard `_` or `_reward`)
 define $Perm($Self) (((true && acc(($Self).claimed,write)) && acc(($Self).count,write)))
 define $Inv($Self) (invariant_7($Self))
 method __init__($Self: Ref)
diff --git a/test/viper/ok/unsupported.tc.ok b/test/viper/ok/unsupported.tc.ok
new file mode 100644
index 00000000000..a9b46438288
--- /dev/null
+++ b/test/viper/ok/unsupported.tc.ok
@@ -0,0 +1 @@
+unsupported.mo:5.7-5.8: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
diff --git a/test/viper/ok/unsupported.vpr.ok b/test/viper/ok/unsupported.vpr.ok
index 30d4be4428b..b01792b2298 100644
--- a/test/viper/ok/unsupported.vpr.ok
+++ b/test/viper/ok/unsupported.vpr.ok
@@ -1,3 +1,4 @@
+unsupported.mo:5.7-5.8: warning [M0194], unused identifier x (delete or rename to wildcard `_` or `_x`)
 unsupported.mo:5.3-5.13: viper error [0], translation to viper failed:
 (LetD (VarP x) (LitE (TextLit )))