diff --git a/include/xrpl/telemetry/Telemetry.h b/include/xrpl/telemetry/Telemetry.h
index 92f87f7a70..1b965345a9 100644
--- a/include/xrpl/telemetry/Telemetry.h
+++ b/include/xrpl/telemetry/Telemetry.h
@@ -252,7 +252,7 @@ public:
     shouldTraceLedger() const = 0;
 
     /** @return The configured consensus trace correlation strategy. */
-    virtual std::string const&
+    [[nodiscard]] virtual std::string const&
     getConsensusTraceStrategy() const = 0;
 
 #ifdef XRPL_ENABLE_TELEMETRY
diff --git a/src/libxrpl/telemetry/NullTelemetry.cpp b/src/libxrpl/telemetry/NullTelemetry.cpp
index a957330a1a..8283ff97bc 100644
--- a/src/libxrpl/telemetry/NullTelemetry.cpp
+++ b/src/libxrpl/telemetry/NullTelemetry.cpp
@@ -18,6 +18,7 @@
 #endif
 
 #include <memory>
+#include <string>
 #include <utility>
 
 namespace xrpl::telemetry {
@@ -87,7 +88,7 @@ public:
         return false;
     }
 
-    std::string const&
+    [[nodiscard]] std::string const&
     getConsensusTraceStrategy() const override
     {
         return setup_.consensusTraceStrategy;
diff --git a/src/tests/libxrpl/telemetry/SpanGuardFactory.cpp b/src/tests/libxrpl/telemetry/SpanGuardFactory.cpp
index 8567b61d82..aa935b2151 100644
--- a/src/tests/libxrpl/telemetry/SpanGuardFactory.cpp
+++ b/src/tests/libxrpl/telemetry/SpanGuardFactory.cpp
@@ -6,6 +6,7 @@
 #include <cstdint>
 #include <exception>
 #include <stdexcept>
+#include <string>
 #include <utility>
 
 using namespace xrpl;
diff --git a/src/xrpld/app/consensus/RCLConsensus.cpp b/src/xrpld/app/consensus/RCLConsensus.cpp
index dffdc9c8bc..c11d944e50 100644
--- a/src/xrpld/app/consensus/RCLConsensus.cpp
+++ b/src/xrpld/app/consensus/RCLConsensus.cpp
@@ -63,8 +63,10 @@
 #include <xrpl/shamap/SHAMapItem.h>
 #include <xrpl/shamap/SHAMapMissingNode.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
+#include <xrpl/telemetry/SpanGuard.h>
+#include <xrpl/telemetry/SpanNames.h>
 #include <xrpl/telemetry/Telemetry.h>
-#include <xrpl/telemetry/TraceContextPropagator.h>
+#include <xrpl/telemetry/TraceContextPropagator.h>  // IWYU pragma: keep
 
 #include <boost/smart_ptr/intrusive_ptr.hpp>
 
@@ -357,7 +359,7 @@ RCLConsensus::Adaptor::onClose(
         telemetry::cons_span::op::ledgerClose);
     span.setAttribute(
         telemetry::cons_span::attr::ledgerSeq,
-        static_cast<int64_t>(ledger.ledger_->header().seq + 1));
+        static_cast<int64_t>(ledger.ledger_->header().seq) + 1);
     span.setAttribute(telemetry::cons_span::attr::mode, toDisplayString(mode).c_str());
 
     bool const wrongLCL = mode == ConsensusMode::wrongLedger;
@@ -556,7 +558,7 @@ RCLConsensus::Adaptor::doAccept(
         ? acceptSpan->childSpan(telemetry::cons_span::acceptApply)
         : telemetry::SpanGuard::childSpan(telemetry::cons_span::acceptApply, roundSpanContext_);
     doAcceptSpan.setAttribute(
-        telemetry::cons_span::attr::ledgerSeq, static_cast<int64_t>(prevLedger.seq() + 1));
+        telemetry::cons_span::attr::ledgerSeq, static_cast<int64_t>(prevLedger.seq()) + 1);
     doAcceptSpan.setAttribute(
         telemetry::cons_span::attr::closeTime,
         static_cast<int64_t>(consensusCloseTime.time_since_epoch().count()));
@@ -582,9 +584,17 @@ RCLConsensus::Adaptor::doAccept(
         static_cast<int64_t>(rawCloseTimes.peers.size()));
     {
         auto const prevRes = prevLedger.closeTimeResolution();
-        std::string dir = (closeResolution > prevRes) ? "increased"
-            : (closeResolution < prevRes)             ? "decreased"
-                                                      : "unchanged";
+        auto const dir = [&]() -> std::string {
+            if (closeResolution > prevRes)
+            {
+                return "increased";
+            }
+            if (closeResolution < prevRes)
+            {
+                return "decreased";
+            }
+            return "unchanged";
+        }();
         doAcceptSpan.setAttribute(telemetry::cons_span::attr::resolutionDirection, std::move(dir));
     }
 
@@ -1218,10 +1228,10 @@ RCLConsensus::Adaptor::startRoundTracing(RCLCxLedger const& prevLgr)
         return;
 
     roundSpan_->setAttribute(cons_span::attr::ledgerId, to_string(prevLgr.id()).c_str());
-    roundSpan_->setAttribute(cons_span::attr::ledgerSeq, static_cast<int64_t>(prevLgr.seq() + 1));
+    roundSpan_->setAttribute(cons_span::attr::ledgerSeq, static_cast<int64_t>(prevLgr.seq()) + 1);
     roundSpan_->setAttribute(cons_span::attr::mode, toDisplayString(mode_.load()).c_str());
     roundSpan_->setAttribute(cons_span::attr::traceStrategy, strategy.c_str());
-    roundSpan_->setAttribute(cons_span::attr::roundId, static_cast<int64_t>(prevLgr.seq() + 1));
+    roundSpan_->setAttribute(cons_span::attr::roundId, static_cast<int64_t>(prevLgr.seq()) + 1);
 
     roundSpanContext_ = roundSpan_->captureContext();
 }
diff --git a/src/xrpld/app/misc/TxSpanNames.h b/src/xrpld/app/misc/TxSpanNames.h
index 2cfd6527d0..091213959e 100644
--- a/src/xrpld/app/misc/TxSpanNames.h
+++ b/src/xrpld/app/misc/TxSpanNames.h
@@ -17,9 +17,7 @@
 
 #include <xrpl/telemetry/SpanNames.h>
 
-namespace xrpl {
-namespace telemetry {
-namespace tx_span {
+namespace xrpl::telemetry::tx_span {
 
 // ===== Span prefixes =======================================================
 
@@ -72,6 +70,4 @@ inline constexpr auto async = makeStr("async");
 inline constexpr auto knownBad = makeStr("known_bad");
 }  // namespace val
 
-}  // namespace tx_span
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry::tx_span
diff --git a/src/xrpld/app/misc/detail/TxQ.cpp b/src/xrpld/app/misc/detail/TxQ.cpp
index 484e14bed2..e263eba22a 100644
--- a/src/xrpld/app/misc/detail/TxQ.cpp
+++ b/src/xrpld/app/misc/detail/TxQ.cpp
@@ -6,6 +6,7 @@
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/basics/Log.h>
+#include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/contract.h>
 #include <xrpl/basics/mulDiv.h>
 #include <xrpl/beast/utility/Zero.h>
@@ -30,7 +31,6 @@
 #include <xrpl/protocol/Units.h>
 #include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
-#include <xrpl/protocol/st.h>
 #include <xrpl/telemetry/SpanGuard.h>
 #include <xrpl/tx/apply.h>
 #include <xrpl/tx/applySteps.h>
diff --git a/src/xrpld/app/misc/detail/TxQSpanNames.h b/src/xrpld/app/misc/detail/TxQSpanNames.h
index 6989674341..4f18e82ae7 100644
--- a/src/xrpld/app/misc/detail/TxQSpanNames.h
+++ b/src/xrpld/app/misc/detail/TxQSpanNames.h
@@ -48,9 +48,7 @@
 
 #include <xrpl/telemetry/SpanNames.h>
 
-namespace xrpl {
-namespace telemetry {
-namespace txq_span {
+namespace xrpl::telemetry::txq_span {
 
 // ===== Span prefixes =======================================================
 
@@ -110,6 +108,4 @@ inline constexpr auto failed = makeStr("failed");
 inline constexpr auto retried = makeStr("retried");
 }  // namespace val
 
-}  // namespace txq_span
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry::txq_span
diff --git a/src/xrpld/consensus/Consensus.h b/src/xrpld/consensus/Consensus.h
index a32cdd2c0c..f6bb1ecb22 100644
--- a/src/xrpld/consensus/Consensus.h
+++ b/src/xrpld/consensus/Consensus.h
@@ -1801,11 +1801,17 @@ Consensus<Adaptor>::haveConsensus(std::unique_ptr<std::stringstream> const& clog
 
     char const* stateStr = "no";
     if (result_->state == ConsensusState::Yes)
+    {
         stateStr = "yes";
+    }
     else if (result_->state == ConsensusState::MovedOn)
+    {
         stateStr = "moved_on";
+    }
     else if (result_->state == ConsensusState::Expired)
+    {
         stateStr = "expired";
+    }
     span.setAttribute(cons_span::attr::result, stateStr);
 
     CLOG(clog) << "Consensus has been reached. ";
diff --git a/src/xrpld/consensus/ConsensusSpanNames.h b/src/xrpld/consensus/ConsensusSpanNames.h
index 868f730860..b3112af1ec 100644
--- a/src/xrpld/consensus/ConsensusSpanNames.h
+++ b/src/xrpld/consensus/ConsensusSpanNames.h
@@ -78,9 +78,7 @@
 
 #include <xrpl/telemetry/SpanNames.h>
 
-namespace xrpl {
-namespace telemetry {
-namespace cons_span {
+namespace xrpl::telemetry::cons_span {
 
 // ===== Span name segments ====================================================
 
@@ -240,6 +238,4 @@ inline constexpr auto decreased = makeStr("decreased");
 inline constexpr auto unchanged = makeStr("unchanged");
 }  // namespace val
 
-}  // namespace cons_span
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry::cons_span
diff --git a/src/xrpld/consensus/DisputedTx.h b/src/xrpld/consensus/DisputedTx.h
index 2629feef5e..fcd2b0ebac 100644
--- a/src/xrpld/consensus/DisputedTx.h
+++ b/src/xrpld/consensus/DisputedTx.h
@@ -177,14 +177,14 @@ public:
     getJson() const;
 
     //! Number of peers voting yes.
-    int
+    [[nodiscard]] int
     getYays() const
     {
         return yays_;
     }
 
     //! Number of peers voting no.
-    int
+    [[nodiscard]] int
     getNays() const
     {
         return nays_;
diff --git a/src/xrpld/telemetry/ConsensusReceiveTracing.h b/src/xrpld/telemetry/ConsensusReceiveTracing.h
index a53f2685f8..6da9900fab 100644
--- a/src/xrpld/telemetry/ConsensusReceiveTracing.h
+++ b/src/xrpld/telemetry/ConsensusReceiveTracing.h
@@ -39,8 +39,7 @@
 #include <xrpl/proto/xrpl.pb.h>
 #include <xrpl/telemetry/SpanGuard.h>
 
-namespace xrpl {
-namespace telemetry {
+namespace xrpl::telemetry {
 
 // Inline span name constants for consensus receive spans.
 // Phase 4 will provide these via ConsensusSpanNames.h; these are
@@ -123,5 +122,4 @@ validationReceiveSpan([[maybe_unused]] protocol::TMValidation const& msg)
     return SpanGuard::span(TraceCategory::Consensus, "consensus", "validation.receive");
 }
 
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry
diff --git a/src/xrpld/telemetry/PropagationHelpers.h b/src/xrpld/telemetry/PropagationHelpers.h
index c051026b74..44959ae039 100644
--- a/src/xrpld/telemetry/PropagationHelpers.h
+++ b/src/xrpld/telemetry/PropagationHelpers.h
@@ -32,8 +32,7 @@
 #include <xrpl/proto/xrpl.pb.h>
 #include <xrpl/telemetry/SpanGuard.h>
 
-namespace xrpl {
-namespace telemetry {
+namespace xrpl::telemetry {
 
 /** Inject trace context from an active SpanGuard into a protobuf
  *  TraceContext message for cross-node propagation.
@@ -58,5 +57,4 @@ injectSpanContext(SpanGuard const& span, protocol::TraceContext& proto)
     proto.set_trace_flags(bytes.traceFlags);
 }
 
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry
diff --git a/src/xrpld/telemetry/TxTracing.h b/src/xrpld/telemetry/TxTracing.h
index e466c45a6c..68b4903f88 100644
--- a/src/xrpld/telemetry/TxTracing.h
+++ b/src/xrpld/telemetry/TxTracing.h
@@ -16,8 +16,7 @@
 #include <xrpl/proto/xrpl.pb.h>
 #include <xrpl/telemetry/SpanGuard.h>
 
-namespace xrpl {
-namespace telemetry {
+namespace xrpl::telemetry {
 
 /** Create a "tx.receive" span for a transaction received from a peer.
  *  trace_id is derived from txID[0:16]. If the incoming message carries
@@ -59,5 +58,4 @@ txProcessSpan(uint256 const& txID)
         TraceCategory::Transactions, tx_span::process, txID.data(), txID.bytes);
 }
 
-}  // namespace telemetry
-}  // namespace xrpl
+}  // namespace xrpl::telemetry