diff --git a/include/audacity/EffectInterface.h b/include/audacity/EffectInterface.h
index 8a9134e0e..e31ec6ffa 100755
--- a/include/audacity/EffectInterface.h
+++ b/include/audacity/EffectInterface.h
@@ -64,8 +64,11 @@ public:
    virtual ~EffectIdentInterface() {};
 
    virtual EffectType GetType() = 0;
-   // Returns a string for internal uses only that may persist in config files:
+
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    virtual wxString GetFamilyId() = 0;
+
    // Returns a user-visible string:
    virtual wxString GetFamilyName() = 0;
 
diff --git a/include/audacity/IdentInterface.h b/include/audacity/IdentInterface.h
index 10feb3bef..2032327f8 100644
--- a/include/audacity/IdentInterface.h
+++ b/include/audacity/IdentInterface.h
@@ -51,11 +51,15 @@ public:
 
    // These should return an untranslated value
    virtual wxString GetPath() = 0;
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    virtual wxString GetSymbol() = 0;
 
    // These should return an untranslated value whose translation
    // will be determined at runtime (if available)
    virtual wxString GetName() = 0;
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    virtual wxString GetVendor() = 0;
    virtual wxString GetVersion() = 0;
 
diff --git a/src/PluginManager.cpp b/src/PluginManager.cpp
index 1537b1622..4499d915c 100644
--- a/src/PluginManager.cpp
+++ b/src/PluginManager.cpp
@@ -2616,6 +2616,8 @@ PluginID PluginManager::GetID(ImporterInterface *importer)
                            importer->GetPath());
 }
 
+// This string persists in configuration files
+// So config compatibility will break if it is changed across Audacity versions
 wxString PluginManager::GetPluginTypeString(PluginType type)
 {
    wxString str;
@@ -2888,6 +2890,11 @@ bool PluginManager::SetConfig(const wxString & key, const double & value)
 /* Return value is a key for lookup in a config file */
 wxString PluginManager::SettingsPath(const PluginID & ID, bool shared)
 {
+   // All the strings reported by PluginDescriptor and used in this function
+   // persist in the plugin settings configuration file, so they should not
+   // be changed across Audacity versions, or else compatibility of the
+   // configuration files will break.
+
    if (mPlugins.find(ID) == mPlugins.end())
    {
       return wxEmptyString;
diff --git a/src/PluginManager.h b/src/PluginManager.h
index 276a81465..458b939d2 100644
--- a/src/PluginManager.h
+++ b/src/PluginManager.h
@@ -91,6 +91,8 @@ public:
 
    // Internal string only, no translated counterpart!
    // (Use Effect::GetFamilyName instead)
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    wxString GetEffectFamilyId() const;
 
    EffectType GetEffectType() const;
@@ -237,6 +239,8 @@ public:
    static PluginID GetID(EffectIdentInterface *effect);
    static PluginID GetID(ImporterInterface *importer);
 
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    static wxString GetPluginTypeString(PluginType type);
 
    int GetPluginCount(PluginType type);
diff --git a/src/effects/Effect.h b/src/effects/Effect.h
index ed940dae1..bf484da84 100644
--- a/src/effects/Effect.h
+++ b/src/effects/Effect.h
@@ -78,7 +78,11 @@ class AUDACITY_DLL_API Effect /* not final */ : public wxEvtHandler,
    // IdentInterface implementation
 
    wxString GetPath() override;
+
+   // This string persists in configuration files
+   // So config compatibility will break if it is changed across Audacity versions
    wxString GetSymbol() override;
+
    wxString GetName() override;
    wxString GetVendor() override;
    wxString GetVersion() override;