diff --git a/ortools/algorithms/radix_sort.h b/ortools/algorithms/radix_sort.h
index 419bd930ef..a0c1663252 100644
--- a/ortools/algorithms/radix_sort.h
+++ b/ortools/algorithms/radix_sort.h
@@ -51,7 +51,7 @@
 namespace operations_research {
 
 // Sorts an array of int, double, or other numeric types. Up to ~10x faster than
-// std::sort() when size ≥ 8k: go/radix-sort-bench. See file-level comment.
+// std::sort() when size ≥ 8k. See file-level comment for more details.
 template <typename T>
 void RadixSort(
     absl::Span<T> values,
diff --git a/ortools/base/int_type.h b/ortools/base/int_type.h
index 57a990a716..eb5927e64b 100644
--- a/ortools/base/int_type.h
+++ b/ortools/base/int_type.h
@@ -189,7 +189,6 @@ class IntType {
   }
 
   // Note that this may change from time to time without notice.
-  // See .
   struct Hasher {
     size_t operator()(const IntType& arg) const {
       return static_cast<size_t>(arg.value());
diff --git a/ortools/constraint_solver/csharp/IntVarArrayHelper.cs b/ortools/constraint_solver/csharp/IntVarArrayHelper.cs
index 1c1711cb7d..bc32203bf9 100644
--- a/ortools/constraint_solver/csharp/IntVarArrayHelper.cs
+++ b/ortools/constraint_solver/csharp/IntVarArrayHelper.cs
@@ -174,7 +174,7 @@ public static class IntVarArrayHelper
     }
 }
 
-// TODO(user): Try to move this code back to the .i with @define macros.
+// TODO(user): Try to move this code back to the .swig with @define macros.
 public partial class IntVarVector : IDisposable,
                                     System.Collections.IEnumerable
 #if !SWIG_DOTNET_1
diff --git a/ortools/constraint_solver/search_limit.proto b/ortools/constraint_solver/search_limit.proto
index fc78a2e35b..f1d7fe9d16 100644
--- a/ortools/constraint_solver/search_limit.proto
+++ b/ortools/constraint_solver/search_limit.proto
@@ -20,7 +20,7 @@ option java_package = "com.google.ortools.constraintsolver";
 option java_multiple_files = true;
 // We set the outer classname to something other than 'SearchLimit', which is
 // in conflict with the SWIG-generated class in the same directory (see
-// java/constraint_solver.i).
+// java/constraint_solver.swig).
 option java_outer_classname = "SearchLimitProtobuf";
 option csharp_namespace = "Google.OrTools.ConstraintSolver";
 
diff --git a/ortools/graph/graph.h b/ortools/graph/graph.h
index db3f0e2bcb..abc6b09279 100644
--- a/ortools/graph/graph.h
+++ b/ortools/graph/graph.h
@@ -638,8 +638,6 @@ struct GraphTraits {
 //   + (ArcIndexType + NodeIndexType) * arc_capacity().
 // - Has an efficient Tail() but need an extra NodeIndexType/arc memory for it.
 // - Never changes the initial arc index returned by AddArc().
-//
-// All graphs should be -compatible, but we haven't tested that.
 template <typename NodeIndexType = int32_t, typename ArcIndexType = int32_t>
 class ListGraph : public BaseGraph<NodeIndexType, ArcIndexType, false> {
   typedef BaseGraph<NodeIndexType, ArcIndexType, false> Base;
diff --git a/ortools/graph/graph_io.h b/ortools/graph/graph_io.h
index 82a2002a5e..36dee1c110 100644
--- a/ortools/graph/graph_io.h
+++ b/ortools/graph/graph_io.h
@@ -17,7 +17,9 @@
 #define UTIL_GRAPH_IO_H_
 
 #include <algorithm>
+#include <cstddef>
 #include <cstdint>
+#include <cstdio>
 #include <memory>
 #include <numeric>
 #include <string>
@@ -29,10 +31,9 @@
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
 #include "absl/strings/str_join.h"
-#include "absl/strings/str_split.h"
+#include "absl/strings/string_view.h"
 #include "absl/types/span.h"
 #include "ortools/base/numbers.h"
-#include "ortools/graph/graph.h"
 #include "ortools/util/filelineiter.h"
 
 namespace util {
diff --git a/ortools/graph/topologicalsorter.h b/ortools/graph/topologicalsorter.h
index 1297e5bf9f..3189a76d2a 100644
--- a/ortools/graph/topologicalsorter.h
+++ b/ortools/graph/topologicalsorter.h
@@ -313,8 +313,6 @@ typedef ::util::internal::DenseIntTopologicalSorterTpl<
 // TopologicalSorter requires that all nodes and edges be added before
 // traversing the nodes, otherwise it will die with a fatal error.
 //
-// TopologicalSorter is -compatible
-//
 // Note(user): since all the real work is done by
 // DenseIntTopologicalSorterTpl, and this class is a template, we inline
 // every function here in the .h.
diff --git a/ortools/graph/util.h b/ortools/graph/util.h
index 3014f85ad3..26a5449c03 100644
--- a/ortools/graph/util.h
+++ b/ortools/graph/util.h
@@ -18,18 +18,17 @@
 
 #include <algorithm>
 #include <cstdint>
-#include <map>
+#include <limits>
 #include <memory>
 #include <set>
-#include <string>
 #include <utility>
 #include <vector>
 
 #include "absl/container/btree_map.h"
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/inlined_vector.h"
+#include "absl/log/check.h"
 #include "absl/types/span.h"
-#include "ortools/base/hash.h"
 #include "ortools/base/map_util.h"
 #include "ortools/graph/connected_components.h"
 #include "ortools/graph/graph.h"
diff --git a/ortools/linear_solver/scip_interface.cc b/ortools/linear_solver/scip_interface.cc
index cd3b5390d6..5a3c573ea5 100644
--- a/ortools/linear_solver/scip_interface.cc
+++ b/ortools/linear_solver/scip_interface.cc
@@ -20,20 +20,19 @@
 #include <cstdint>
 #include <limits>
 #include <memory>
-#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "absl/base/attributes.h"
 #include "absl/cleanup/cleanup.h"
+#include "absl/flags/flag.h"
 #include "absl/status/status.h"
 #include "absl/strings/str_format.h"
-#include "absl/types/optional.h"
-#include "ortools/base/commandlineflags.h"
-#include "ortools/base/hash.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/time/time.h"
+#include "lpi/lpi.h"
 #include "ortools/base/logging.h"
-#include "ortools/base/status_macros.h"
 #include "ortools/base/timer.h"
 #include "ortools/gscip/legacy_scip_params.h"
 #include "ortools/linear_solver/linear_solver.h"
@@ -45,12 +44,29 @@
 #include "ortools/linear_solver/scip_helper_macros.h"
 #include "ortools/util/lazy_mutable_copy.h"
 #include "scip/cons_indicator.h"
-#include "scip/scip.h"
+#include "scip/cons_linear.h"
+#include "scip/def.h"
+#include "scip/scip_cons.h"
 #include "scip/scip_copy.h"
+#include "scip/scip_general.h"
+#include "scip/scip_message.h"
 #include "scip/scip_numerics.h"
 #include "scip/scip_param.h"
 #include "scip/scip_prob.h"
+#include "scip/scip_sol.h"
+#include "scip/scip_solve.h"
+#include "scip/scip_solvingstats.h"
+#include "scip/scip_var.h"
 #include "scip/scipdefplugins.h"
+#include "scip/type_clock.h"
+#include "scip/type_cons.h"
+#include "scip/type_paramset.h"
+#include "scip/type_prob.h"
+#include "scip/type_retcode.h"
+#include "scip/type_scip.h"
+#include "scip/type_sol.h"
+#include "scip/type_stat.h"
+#include "scip/type_var.h"
 
 ABSL_FLAG(bool, scip_feasibility_emphasis, false,
           "When true, emphasize search towards feasibility. This may or "
@@ -98,11 +114,11 @@ class SCIPInterface : public MPSolverInterface {
 
   int64_t iterations() const override;
   int64_t nodes() const override;
-  MPSolver::BasisStatus row_status(int constraint_index) const override {
+  MPSolver::BasisStatus row_status(int) const override {
     LOG(DFATAL) << "Basis status only available for continuous problems";
     return MPSolver::FREE;
   }
-  MPSolver::BasisStatus column_status(int variable_index) const override {
+  MPSolver::BasisStatus column_status(int) const override {
     LOG(DFATAL) << "Basis status only available for continuous problems";
     return MPSolver::FREE;
   }
@@ -445,15 +461,12 @@ void SCIPInterface::ClearConstraint(MPConstraint* constraint) {
 }
 
 // Cached
-void SCIPInterface::SetObjectiveCoefficient(const MPVariable* variable,
-                                            double coefficient) {
+void SCIPInterface::SetObjectiveCoefficient(const MPVariable*, double) {
   sync_status_ = MUST_RELOAD;
 }
 
 // Cached
-void SCIPInterface::SetObjectiveOffset(double value) {
-  sync_status_ = MUST_RELOAD;
-}
+void SCIPInterface::SetObjectiveOffset(double) { sync_status_ = MUST_RELOAD; }
 
 // Clear objective of all its terms.
 void SCIPInterface::ClearObjective() {
@@ -492,16 +505,16 @@ void SCIPInterface::BranchingPriorityChangedForVariable(int var_index) {
   }
 }
 
-void SCIPInterface::AddRowConstraint(MPConstraint* ct) {
+void SCIPInterface::AddRowConstraint(MPConstraint*) {
   sync_status_ = MUST_RELOAD;
 }
 
-bool SCIPInterface::AddIndicatorConstraint(MPConstraint* ct) {
+bool SCIPInterface::AddIndicatorConstraint(MPConstraint*) {
   sync_status_ = MUST_RELOAD;
   return true;
 }
 
-void SCIPInterface::AddVariable(MPVariable* var) { sync_status_ = MUST_RELOAD; }
+void SCIPInterface::AddVariable(MPVariable*) { sync_status_ = MUST_RELOAD; }
 
 void SCIPInterface::ExtractNewVariables() {
   RETURN_IF_ALREADY_IN_ERROR_STATE;
@@ -882,7 +895,7 @@ bool SCIPInterface::SupportsDirectlySolveProto(
 }
 
 MPSolutionResponse SCIPInterface::DirectlySolveProto(
-    LazyMutableCopy<MPModelRequest> request, std::atomic<bool>* interrupt) {
+    LazyMutableCopy<MPModelRequest> request, std::atomic<bool>*) {
   const bool log_error = request->enable_internal_solver_output();
   return ConvertStatusOrMPSolutionResponse(log_error,
                                            ScipSolveProto(std::move(request)));
@@ -976,7 +989,7 @@ void SCIPInterface::SetPresolveMode(int presolve) {
   }
 }
 
-void SCIPInterface::SetScalingMode(int scaling) {
+void SCIPInterface::SetScalingMode(int) {
   SetUnsupportedIntegerParam(MPSolverParameters::SCALING);
 }
 
diff --git a/ortools/linear_solver/wrappers/model_builder_helper.h b/ortools/linear_solver/wrappers/model_builder_helper.h
index 4f2371da2c..4d5d9579ed 100644
--- a/ortools/linear_solver/wrappers/model_builder_helper.h
+++ b/ortools/linear_solver/wrappers/model_builder_helper.h
@@ -309,7 +309,7 @@ class BoundedLinearExpression {
 // to be wrapped by SWIG correctly:
 // 1) Their types must include the full operations_research::
 //    namespace.
-// 2) Their names must correspond to the ones declared in the .i
+// 2) Their names must correspond to the ones declared in the .swig
 //    file (see the java/ and csharp/ subdirectories).
 
 // Helper for importing/exporting models and model protobufs.
diff --git a/ortools/util/piecewise_linear_function.h b/ortools/util/piecewise_linear_function.h
index da473af65f..297e6e9332 100644
--- a/ortools/util/piecewise_linear_function.h
+++ b/ortools/util/piecewise_linear_function.h
@@ -105,7 +105,7 @@ class PiecewiseLinearFunction {
 
   // This API provides a factory for creating different families of Piecewise
   // Linear Functions based on specific properties of each family. The
-  // PiecewiseLinearFunction is composed by a set of PiecwiseSegments and upon
+  // PiecewiseLinearFunction is composed by a set of PiecewiseSegments and upon
   // creation is not modifiable but with the provided function operations.
   // The object returned by any of these builders in the factory is owned by
   // the client code.