diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
index eed996f0..d1e72ef6 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_Cocoa.swift
@@ -386,7 +386,7 @@ private extension VwrCandidateTDKCocoa {
 
 private extension VwrCandidateTDKCocoa {
   func didSelectCandidateAt(_ pos: Int) {
-    controller?.delegate?.candidatePairSelected(at: pos)
+    controller?.delegate?.candidatePairSelectionConfirmed(at: pos)
   }
 
   func didRightClickCandidateAt(_ pos: Int, action: CandidateContextMenuAction) {
diff --git a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
index 7ff1a548..de38d0b1 100644
--- a/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
+++ b/Packages/vChewing_CandidateWindow/Sources/CandidateWindow/TDKCandidates/VwrCandidateTDK_SwiftUI.swift
@@ -350,7 +350,7 @@ extension VwrCandidateTDK {
 @available(macOS 10.15, *)
 private extension VwrCandidateTDK {
   func didSelectCandidateAt(_ pos: Int) {
-    controller?.delegate?.candidatePairSelected(at: pos)
+    controller?.delegate?.candidatePairSelectionConfirmed(at: pos)
   }
 
   func didRightClickCandidateAt(_ pos: Int, action: CandidateContextMenuAction) {
diff --git a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
index 8a86522d..7e8e96f4 100644
--- a/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
+++ b/Packages/vChewing_Shared/Sources/Shared/Protocols/CtlCandidateProtocol.swift
@@ -10,7 +10,8 @@ import Cocoa
 
 public protocol CtlCandidateDelegate {
   func candidatePairs(conv: Bool) -> [(keyArray: [String], value: String)]
-  func candidatePairSelected(at index: Int)
+  func candidatePairSelectionConfirmed(at index: Int)
+  func candidatePairHighlightChanged(at index: Int)
   func candidatePairRightClicked(at index: Int, action: CandidateContextMenuAction)
   func candidates(_ sender: Any!) -> [Any]!
   @discardableResult func reverseLookup(for value: String) -> [String]
diff --git a/Source/Modules/InputHandler_Core.swift b/Source/Modules/InputHandler_Core.swift
index c3675e4d..ee753b00 100644
--- a/Source/Modules/InputHandler_Core.swift
+++ b/Source/Modules/InputHandler_Core.swift
@@ -66,7 +66,7 @@ public protocol InputHandlerDelegate {
   func updateVerticalTypingStatus()
   func switchState(_ newState: IMEStateProtocol)
   func candidateController() -> CtlCandidateProtocol?
-  func candidateSelectionCalledByInputHandler(at index: Int)
+  func candidateSelectionConfirmedByInputHandler(at index: Int)
   func performUserPhraseOperation(addToFilter: Bool)
     -> Bool
 }
diff --git a/Source/Modules/InputHandler_HandleCandidate.swift b/Source/Modules/InputHandler_HandleCandidate.swift
index 8a9a4035..5fd10221 100644
--- a/Source/Modules/InputHandler_HandleCandidate.swift
+++ b/Source/Modules/InputHandler_HandleCandidate.swift
@@ -62,7 +62,7 @@ extension InputHandler {
           delegate.switchState(IMEState.ofAbortion())
           return true
         }
-        delegate.candidateSelectionCalledByInputHandler(at: ctlCandidate.highlightedIndex)
+        delegate.candidateSelectionConfirmedByInputHandler(at: ctlCandidate.highlightedIndex)
         return true
       case .kTab:
         let updated: Bool =
@@ -142,7 +142,7 @@ extension InputHandler {
 
     if index != NSNotFound {
       if let candidateIndex = ctlCandidate.candidateIndexAtKeyLabelIndex(index) {
-        delegate.candidateSelectionCalledByInputHandler(at: candidateIndex)
+        delegate.candidateSelectionConfirmedByInputHandler(at: candidateIndex)
         return true
       }
     }
@@ -185,7 +185,7 @@ extension InputHandler {
 
       if shouldAutoSelectCandidate {
         guard let candidateIndex = ctlCandidate.candidateIndexAtKeyLabelIndex(0) else { return true }
-        delegate.candidateSelectionCalledByInputHandler(at: candidateIndex)
+        delegate.candidateSelectionConfirmedByInputHandler(at: candidateIndex)
         delegate.switchState(IMEState.ofAbortion())
         return handleInput(event: input)
       }
diff --git a/Source/Modules/SessionCtl_Delegates.swift b/Source/Modules/SessionCtl_Delegates.swift
index 3f19d6f6..2068e7f5 100644
--- a/Source/Modules/SessionCtl_Delegates.swift
+++ b/Source/Modules/SessionCtl_Delegates.swift
@@ -22,8 +22,8 @@ extension SessionCtl: InputHandlerDelegate {
 
   public func candidateController() -> CtlCandidateProtocol? { candidateUI }
 
-  public func candidateSelectionCalledByInputHandler(at index: Int) {
-    candidatePairSelected(at: index)
+  public func candidateSelectionConfirmedByInputHandler(at index: Int) {
+    candidatePairSelectionConfirmed(at: index)
   }
 
   public func callError(_ logMessage: String) {
@@ -108,7 +108,9 @@ extension SessionCtl: CtlCandidateDelegate {
     return convertedCandidates
   }
 
-  public func candidatePairSelected(at index: Int) {
+  public func candidatePairHighlightChanged(at _: Int) {}
+
+  public func candidatePairSelectionConfirmed(at index: Int) {
     guard let inputHandler = inputHandler else { return }
     if state.type == .ofSymbolTable, (0 ..< state.node.members.count).contains(index) {
       let node = state.node.members[index]
diff --git a/Source/Modules/SessionCtl_IMKCandidatesData.swift b/Source/Modules/SessionCtl_IMKCandidatesData.swift
index 1b39945d..69abe2b5 100644
--- a/Source/Modules/SessionCtl_IMKCandidatesData.swift
+++ b/Source/Modules/SessionCtl_IMKCandidatesData.swift
@@ -80,6 +80,7 @@ public extension SessionCtl {
   }
 
   /// IMK 選字窗限定函式，只要選字窗確認了某個候選字詞的選擇、就會呼叫這個函式。
+  /// - Remark: 不要被 IMK 的 API 命名方式困惑到。這其實是 Confirm Selection 確認選字。
   /// - Parameter candidateString: 已經確認的候選字詞內容。
   override func candidateSelected(_ candidateString: NSAttributedString!) {
     let candidateString: String = candidateString?.string ?? ""
@@ -150,6 +151,6 @@ public extension SessionCtl {
         handleIMKCandidatesSelected(state.candidates)
       }
     }
-    candidatePairSelected(at: indexDeducted)
+    candidatePairSelectionConfirmed(at: indexDeducted)
   }
 }