diff --git a/app/src/qt/dialogs/configuration_dialog.cpp b/app/src/qt/dialogs/configuration_dialog.cpp
index b63572a5..784c01ae 100644
--- a/app/src/qt/dialogs/configuration_dialog.cpp
+++ b/app/src/qt/dialogs/configuration_dialog.cpp
@@ -709,6 +709,7 @@ ConfigurationDialog::WingmanOpenAiTab::WingmanOpenAiTab(QWidget* parent, QComboB
     setOpenAiButton->setVisible(helpLabel->isVisible());
     clearApiKeyButton = new QPushButton(tr("Clear API Key"), this);
     clearApiKeyButton->setVisible(helpLabel->isVisible());
+    // LLM model can be choose at any time when a valid configuration is available
     llmModelsLabel = new QLabel(tr("LLM model:"));
     llmModelsCombo = new QComboBox();
     llmModelsCombo->addItem(LLM_MODEL_NONE);
@@ -1006,7 +1007,7 @@ void ConfigurationDialog::WingmanTab::handleComboBoxChanged(int index) {
             tr(
                 "You have chosen OpenAI as your Wingman LLM provider. "
                 "Therefore, your data will be sent to OpenAI servers "
-                "for GPT processing when you use Wingman."));
+                "when you use Wingman."));
     }
 }
 
diff --git a/app/src/qt/main_menu_presenter.cpp b/app/src/qt/main_menu_presenter.cpp
index 5635c4a0..3b2e0927 100644
--- a/app/src/qt/main_menu_presenter.cpp
+++ b/app/src/qt/main_menu_presenter.cpp
@@ -115,6 +115,7 @@ MainMenuPresenter::MainMenuPresenter(MainWindowPresenter* mwp)
     // menu: Library
     QObject::connect(view->actionLibraryAdd, SIGNAL(triggered()), mwp, SLOT(doActionLibraryNew()));
     QObject::connect(view->actionLibrarySync, SIGNAL(triggered()), mwp, SLOT(doActionLibrarySync()));
+    QObject::connect(view->actionLibraryOrphans, SIGNAL(triggered()), mwp, SLOT(doActionLibraryOrphans()));
     QObject::connect(view->actionLibraryDeprecate, SIGNAL(triggered()), mwp, SLOT(doActionLibraryRm()));
 
     // menu: Organizer
diff --git a/app/src/qt/main_menu_view.cpp b/app/src/qt/main_menu_view.cpp
index a28d450e..76074cbd 100644
--- a/app/src/qt/main_menu_view.cpp
+++ b/app/src/qt/main_menu_view.cpp
@@ -109,7 +109,7 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
     actionMindAutolink->setVisible(false);
 #endif
 
-    actionMindWingman = new QAction(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman GPT"), mainWindow);
+    actionMindWingman = new QAction(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman LLM"), mainWindow);
     actionMindWingman->setShortcut(QKeySequence(Qt::CTRL+Qt::Key_Slash));
     actionMindWingman->setStatusTip(tr("Open Wingman dialog..."));
 
@@ -140,6 +140,13 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
         tr(
             "Synchronize library source directory with MindForger notebook(s) which represent"
             "library resources..."));
+    // library: find orphans
+    actionLibraryOrphans = new QAction(
+        QIcon(":/menu-icons/find.svg"),
+        tr("&Find orphans"),
+        mainWindow);
+    actionLibrarySync->setStatusTip(
+        tr("Find library Notebooks which reference non-existent documents..."));
     // library: deprecate
     actionLibraryDeprecate = new QAction(
         QIcon(":/menu-icons/delete.svg"), tr("&Delete library"), mainWindow);
@@ -148,6 +155,7 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
     // assemble Library sub-menu
     submenuMindLibrary->addAction(actionLibraryAdd);
     submenuMindLibrary->addAction(actionLibrarySync);
+    submenuMindLibrary->addAction(actionLibraryOrphans);
     submenuMindLibrary->addAction(actionLibraryDeprecate);
 
     // dream ... sanity, integrity, detox, inference, assoc discovery, ...
@@ -565,7 +573,7 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
     actionOutlineTWikiImport->setStatusTip(tr("Import Notebook from an external TWiki file and restart MindForger"));
     submenuOutlineImport->addAction(actionOutlineTWikiImport);
 
-    submenuOutlineWingman = menuOutline->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman GPT"));
+    submenuOutlineWingman = menuOutline->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman LLM"));
     actionOutlineWingmanSummarize = new QAction(tr("&Summarize"), mainWindow);
     actionOutlineWingmanSummarize->setStatusTip(tr("Ask Wingman to summarize text of the Notebook..."));
     submenuOutlineWingman->addAction(actionOutlineWingmanSummarize);
@@ -699,7 +707,7 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
     actionNoteImport->setStatusTip(tr("Import Note from an external file in a supported format"));
     actionNoteImport->setEnabled(false);
 
-    submenuNoteWingman = menuNote->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman GPT"));
+    submenuNoteWingman = menuNote->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman LLM"));
     actionNoteWingmanSummarize = new QAction(tr("&Summarize"), mainWindow);
     actionNoteWingmanSummarize->setStatusTip(tr("Ask Wingman to summarize text of the Note..."));
     submenuNoteWingman->addAction(actionNoteWingmanSummarize);
@@ -788,7 +796,7 @@ MainMenuView::MainMenuView(MainWindowView& mainWindowView)
     actionEditSpellCheck = new QAction(QIcon(":/menu-icons/paste.svg"), tr("&Spell Check"), mainWindow);
     actionEditSpellCheck->setStatusTip(tr("Spell check Notebook or Note description"));
 
-    submenuEditWingman = menuEdit->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman GPT"));
+    submenuEditWingman = menuEdit->addMenu(QIcon(":/menu-icons/wingman-green.svg"), tr("&Wingman LLM"));
     actionEditWingmanFixGrammar = new QAction(tr("&Fix Grammar"), mainWindow);
     actionEditWingmanFixGrammar->setStatusTip(tr("Ask Wingman to fix grammar errors in the selected text / word under the cursor..."));
     submenuEditWingman->addAction(actionEditWingmanFixGrammar);
diff --git a/app/src/qt/main_menu_view.h b/app/src/qt/main_menu_view.h
index e31d09b3..5a7e2065 100644
--- a/app/src/qt/main_menu_view.h
+++ b/app/src/qt/main_menu_view.h
@@ -85,6 +85,7 @@ class MainMenuView : public QObject
     QMenu* submenuMindLibrary;
     QAction* actionLibraryAdd;
     QAction* actionLibrarySync;
+    QAction* actionLibraryOrphans;
     QAction* actionLibraryDeprecate;
     QAction* actionMindPreferences;
     QMenu* submenuMindExport;
diff --git a/app/src/qt/main_window_presenter.cpp b/app/src/qt/main_window_presenter.cpp
index 0b671e57..91521567 100644
--- a/app/src/qt/main_window_presenter.cpp
+++ b/app/src/qt/main_window_presenter.cpp
@@ -2176,13 +2176,13 @@ void MainWindowPresenter::slotRunWingmanFromDialog(bool showDialog)
 
         // check the result
         if (future.isFinished()) {
-            statusBar->showInfo(QString(tr("Wingman received an answer from the GPT provider")));
+            statusBar->showInfo(QString(tr("Wingman received an answer from the LLM provider")));
         } else {
-            statusBar->showError(QString(tr("Wingman failed to receive an answer from the GPT provider")));
+            statusBar->showError(QString(tr("Wingman failed to receive an answer from the LLM provider")));
 
             // PUSH answer to the chat dialog
             this->wingmanDialog->appendAnswerToChat(
-                "Wingman failed to get answer from the GPT provider.<br/><br/>"+commandWingmanChat.answerMarkdown,
+                "Wingman failed to get answer from the LLM provider.<br/><br/>"+commandWingmanChat.answerMarkdown,
                 "",
                 this->wingmanDialog->getContextType(),
                 true
@@ -3464,6 +3464,10 @@ void MainWindowPresenter::handleSyncLibrary()
     rmLibraryDialog->reset();
 }
 
+void MainWindowPresenter::doActionLibraryOrphans()
+{
+    mind->findLibraryOrphanOs();
+}
 
 void MainWindowPresenter::doActionLibraryRm()
 {
diff --git a/app/src/qt/main_window_presenter.h b/app/src/qt/main_window_presenter.h
index 892714fd..1e843c68 100644
--- a/app/src/qt/main_window_presenter.h
+++ b/app/src/qt/main_window_presenter.h
@@ -240,6 +240,7 @@ public slots:
     void doActionLibraryNew();
     void handleNewLibrary();
     void doActionLibrarySync();
+    void doActionLibraryOrphans();
     void handleSyncLibrary();
     void doActionLibraryRm();
     void handleRmLibrary();
diff --git a/app/src/qt/main_window_view.cpp b/app/src/qt/main_window_view.cpp
index e5ec0c7e..b76b7aff 100644
--- a/app/src/qt/main_window_view.cpp
+++ b/app/src/qt/main_window_view.cpp
@@ -24,13 +24,8 @@ MainWindowView::MainWindowView(LookAndFeels& lookAndFeel)
     : QMainWindow(nullptr), // main window has no parent - it is destroyed by main MF class
       lookAndFeel(lookAndFeel)
 {
-#ifdef MF_LLAMA_CPP
-  #define MINDFORGER_GPT " GPT"
-#else
-  #define MINDFORGER_GPT ""
-#endif
     windowTitleSkeleton
-        = "MindForger" MINDFORGER_GPT " - "
+        = "MindForger - "
           +tr("Thinking Notebook")+" - "
           +MINDFORGER_VERSION;
 
diff --git a/lib/src/mind/ai/llm/ollama_wingman.cpp b/lib/src/mind/ai/llm/ollama_wingman.cpp
index ccbc9b48..de27784a 100644
--- a/lib/src/mind/ai/llm/ollama_wingman.cpp
+++ b/lib/src/mind/ai/llm/ollama_wingman.cpp
@@ -55,12 +55,12 @@ void OllamaWingman::curlListModels() {
     if(!this->llmModels.empty()) {
         this->llmModels.clear();
     }
-    
+
     // call to ollama API to list available models
     throw std::runtime_error("OllamaWingman::curlListModels() not implemented");
 }
 
-std::vector<std::string>& OllamaWingman::listModels() 
+std::vector<std::string>& OllamaWingman::listModels()
 {
     if(this->llmModels.empty()) {
         this->curlListModels();
@@ -258,7 +258,7 @@ void OllamaWingman::curlGet(CommandWingmanChat& command) {
         }
         if(httpResponseJSon.contains("response")) {
             httpResponseJSon["response"].get_to(command.answerMarkdown);
-            // TODO ask GPT for HTML formatted response
+            // TODO ask LLM for HTML formatted response
             m8r::replaceAll(
                 "\n",
                 "<br/>",
diff --git a/lib/src/mind/ai/llm/openai_wingman.cpp b/lib/src/mind/ai/llm/openai_wingman.cpp
index f01bf64a..662aa49a 100644
--- a/lib/src/mind/ai/llm/openai_wingman.cpp
+++ b/lib/src/mind/ai/llm/openai_wingman.cpp
@@ -107,7 +107,7 @@ void OpenAiWingman::curlGet(CommandWingmanChat& command) {
 
         */
         nlohmann::json messageSystemJSon{};
-        messageSystemJSon["role"] = "system"; // system (instruct GPT who it is), user (user prompts), assistant (GPT answers)
+        messageSystemJSon["role"] = "system"; // system (instruct LLM who it is), user (user prompts), assistant (LLM answers)
         messageSystemJSon["content"] =
             // "You are a helpful assistant that returns HTML-formatted answers to the user's prompts."
             "You are a helpful assistant."
@@ -196,6 +196,8 @@ void OpenAiWingman::curlGet(CommandWingmanChat& command) {
                 "  '" << command.httpResponse << "'" << endl);
         }
 #else
+        // TODO refactor this section to a generic CURL call which gets: URL, body as C string and returns httpResponse
+
         // set up cURL options
         command.httpResponse.clear();
         curl_easy_setopt(
diff --git a/lib/src/mind/mind.cpp b/lib/src/mind/mind.cpp
index 02784063..9fc392ed 100644
--- a/lib/src/mind/mind.cpp
+++ b/lib/src/mind/mind.cpp
@@ -1502,6 +1502,53 @@ void Mind::initWingman()
     wingmanLlmProvider = WingmanLlmProviders::WINGMAN_PROVIDER_NONE;
 }
 
+void Mind::findLibraryOrphanOs()
+{
+    vector<Outline*> orphanOutlines{};
+    const vector<Outline*>& outlines = memory.getOutlines();
+    const Tag* t = memory.getOntology().findOrCreateTag(
+        MarkdownDocumentRepresentation::TAG_LIB_DOC);
+    MF_DEBUG("Searching ORPHAN library outlines..." << endl);
+    for(Outline* outline:outlines) {
+        if(!outline->hasTag(t)) {
+            continue;
+        }
+
+        const vector<string*>& d = outline->getDescription();
+        if(d.size()>0) {
+            if(d[0]->size() > 0) {
+                // MF_DEBUG("  Orphan: 1st line '" << *d[0] << "'" << endl);
+                if(stringStartsWith(*d[0], MarkdownDocumentRepresentation::PREFIX_1ST_LINE)) {
+                    // extract Markdown link
+                    size_t i{strlen(MarkdownDocumentRepresentation::PREFIX_1ST_LINE)};
+                    string s{
+                        d[0]->substr(
+                            i,
+                            d[0]->size()-i)};
+                    // MF_DEBUG("    '" << s << "'" << endl);
+
+                    // parse Markdown link
+                    string documentPath{};
+                    if(s.size()>4 && s[0]=='[' && s[s.size()-1]==')') {
+                        size_t i;
+                        if((i=s.find("](")) != std::string::npos) {
+                            documentPath = s.substr(i+2,s.size()-3-i);
+                        }
+                    }
+                    if(documentPath.size()) {
+                        MF_DEBUG("    '" << documentPath << "'" << endl);
+                        if(!isFile(documentPath.c_str())) {
+                            MF_DEBUG("      ORPHAN" << endl);
+                            // TODO
+                            detect whether the file exists
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
 Wingman* Mind::getWingman()
 {
     if(this->wingmanLlmProvider != config.getWingmanLlmProvider()) {
diff --git a/lib/src/mind/mind.h b/lib/src/mind/mind.h
index e2146dd3..39854594 100644
--- a/lib/src/mind/mind.h
+++ b/lib/src/mind/mind.h
@@ -38,6 +38,7 @@
 #include "../config/configuration.h"
 #include "../representations/representation_interceptor.h"
 #include "../representations/markdown/markdown_configuration_representation.h"
+#include "../representations/markdown/markdown_document_representation.h"
 
 namespace m8r {
 
@@ -685,6 +686,15 @@ class Mind : public OntologyProvider
      */
     void noteOnRename(const std::string& oldName, const std::string& newName);
 
+    /*
+     * LIBRARY (information source)
+     */
+
+    /**
+     * @brief Find Os which reference non-existent documents.
+     */
+    void findLibraryOrphanOs();
+
     /*
      * WINGMAN
      */
diff --git a/lib/src/representations/markdown/markdown_document_representation.cpp b/lib/src/representations/markdown/markdown_document_representation.cpp
index e3d9f499..03625152 100644
--- a/lib/src/representations/markdown/markdown_document_representation.cpp
+++ b/lib/src/representations/markdown/markdown_document_representation.cpp
@@ -51,12 +51,11 @@ Outline* MarkdownDocumentRepresentation::to(
     }
 
     o->addTag(ontology.findOrCreateTag("pdf"));
-    o->addTag(ontology.findOrCreateTag("library-document"));
+    o->addTag(ontology.findOrCreateTag(TAG_LIB_DOC));
 
     o->addDescriptionLine(
         new string{
-            "This is a notebook for the document: "
-            "[" + documentPath + "](" + documentPath + ")"});
+            string{PREFIX_1ST_LINE} + "[" + documentPath + "](" + documentPath + ")"});
     o->addDescriptionLine(new string{""});
     o->addDescriptionLine(new string{"---"});
     o->addDescriptionLine(new string{""});
diff --git a/lib/src/representations/markdown/markdown_document_representation.h b/lib/src/representations/markdown/markdown_document_representation.h
index 603f4306..93116abb 100644
--- a/lib/src/representations/markdown/markdown_document_representation.h
+++ b/lib/src/representations/markdown/markdown_document_representation.h
@@ -29,6 +29,12 @@ namespace m8r {
 
 class MarkdownDocumentRepresentation
 {
+public:
+
+    static constexpr const auto TAG_LIB_DOC = "library-document";
+
+    static constexpr const auto PREFIX_1ST_LINE = "This is a notebook for the document: ";
+
 private:
     Ontology& ontology;
 
diff --git a/lib/test/src/json/json_test.cpp b/lib/test/src/json/json_test.cpp
index 9122ca1f..d269818d 100644
--- a/lib/test/src/json/json_test.cpp
+++ b/lib/test/src/json/json_test.cpp
@@ -107,7 +107,7 @@ TEST(JSonTestCase, ParseOpenAiResponse)
             && choice["message"].contains("content")
         ) {
             choice["message"]["content"].get_to(answerMarkdown);
-            // TODO ask GPT for HTML formatted response
+            // TODO ask LLM for HTML formatted response
             m8r::replaceAll(
                 "\n",
                 "<br/>",