diff --git a/app/common/clamp.h b/app/common/clamp.h
index b87fe1657..b5e891bd9 100644
--- a/app/common/clamp.h
+++ b/app/common/clamp.h
@@ -2,6 +2,16 @@
 #define CLAMP_H
 
 template<typename T>
+/**
+ * @brief Clamp a value between a minimum and a maximum value
+ *
+ * Similar to using min() and max() functions, but performs both at once. If value is less than minimum, this returns
+ * minimum. If it is more than maximum, this returns maximum. Otherwise it returns value as-is.
+ *
+ * @return
+ *
+ * Will always return a value between minimum and maximum (inclusive).
+ */
 T clamp(T value, T minimum, T maximum) {
   if (value < minimum) {
     return minimum;
diff --git a/app/common/lerp.h b/app/common/lerp.h
index f84ecbcf9..4d98db0a1 100644
--- a/app/common/lerp.h
+++ b/app/common/lerp.h
@@ -2,6 +2,9 @@
 #define LERP_H
 
 template<typename T>
+/**
+ * @brief Linearly interpolate a value between a and b using t
+ */
 T lerp(T a, T b, double t) {
   return (a * (1.0 - t)) + (b * t);
 }
diff --git a/app/decoder/ffmpeg/ffmpegdecoder.h b/app/decoder/ffmpeg/ffmpegdecoder.h
index bc750dce8..46b3fc9cc 100644
--- a/app/decoder/ffmpeg/ffmpegdecoder.h
+++ b/app/decoder/ffmpeg/ffmpegdecoder.h
@@ -25,6 +25,9 @@
 
 #include "decoder/decoder.h"
 
+/**
+ * @brief A Decoder derivative that wraps FFmpeg functions as on Olive decoder
+ */
 class FFmpegDecoder : public Decoder
 {
 public:
diff --git a/app/decoder/frame.h b/app/decoder/frame.h
index 1fde58258..6992ebbac 100644
--- a/app/decoder/frame.h
+++ b/app/decoder/frame.h
@@ -30,7 +30,9 @@ extern "C" {
 #include "common/rational.h"
 
 /**
- * @brief Abstraction from AVFrame. Currently a simple AVFrame wrapper.
+ * @brief Video frame data or audio sample data from a Decoder
+ *
+ * Abstraction from AVFrame. Currently a simple AVFrame wrapper.
  *
  * This class does not support copying at this time.
  */
diff --git a/app/node/edge.h b/app/node/edge.h
index a6b747135..1bbe8dc20 100644
--- a/app/node/edge.h
+++ b/app/node/edge.h
@@ -26,12 +26,28 @@
 class NodeOutput;
 class NodeInput;
 
+/**
+ * @brief A connection between two node parameters (a NodeOutput and a NodeInput)
+ *
+ * To simplify memory management, it's recommended to use NodeEdgePtr instead of raw pointers when working with
+ * NodeEdge.
+ */
 class NodeEdge
 {
 public:
+  /**
+   * @brief Create a node edge connecting an output to an input
+   */
   NodeEdge(NodeOutput* output, NodeInput* input);
 
+  /**
+   * @brief Return the output parameter this edge is connected to
+   */
   NodeOutput* output();
+
+  /**
+   * @brief Return the input parameter this edge is connected to
+   */
   NodeInput* input();
 
 private:
diff --git a/app/node/generator/solid/solid.cpp b/app/node/generator/solid/solid.cpp
index 2a785ce9c..f284d7790 100644
--- a/app/node/generator/solid/solid.cpp
+++ b/app/node/generator/solid/solid.cpp
@@ -17,6 +17,11 @@ QString SolidGenerator::Name()
   return tr("Solid");
 }
 
+QString SolidGenerator::id()
+{
+  return "org.olivevideoeditor.Olive.solidgenerator";
+}
+
 QString SolidGenerator::Category()
 {
   return tr("Generator");
diff --git a/app/node/generator/solid/solid.h b/app/node/generator/solid/solid.h
index 6c6f7bf62..fd378d1ff 100644
--- a/app/node/generator/solid/solid.h
+++ b/app/node/generator/solid/solid.h
@@ -5,6 +5,9 @@
 
 #include "node/node.h"
 
+/**
+ * @brief A node that generates a solid color
+ */
 class SolidGenerator : public Node
 {
   Q_OBJECT
@@ -12,6 +15,7 @@ public:
   SolidGenerator();
 
   virtual QString Name() override;
+  virtual QString id() override;
   virtual QString Category() override;
   virtual QString Description() override;
 
diff --git a/app/node/graph.h b/app/node/graph.h
index e6215e86a..0d5064829 100644
--- a/app/node/graph.h
+++ b/app/node/graph.h
@@ -25,21 +25,50 @@
 
 #include "node/node.h"
 
+/**
+ * @brief A collection of nodes
+ */
 class NodeGraph : public QObject
 {
   Q_OBJECT
 public:
+  /**
+   * @brief NodeGraph Constructor
+   */
   NodeGraph();
 
+  /**
+   * @brief Add a node to this graph
+   *
+   * The node will get added to this graph. It is not automatically connected to anything, any connections will need to
+   * be made manually after the node is added. The graph takes ownership of the Node.
+   */
   void AddNode(Node* node);
 
+  /**
+   * @brief Return the name of this graph (user-defined)
+   */
   const QString& name();
+
+  /**
+   * @brief Set the name of this graph (user-defined)
+   */
   void set_name(const QString& name);
 
+  /**
+   * @brief Retrieve a complete list of the nodes belonging to this graph
+   */
   QList<Node*> nodes();
 
 signals:
+  /**
+   * @brief Signal emitted when a member node of this graph has been connected to another (creating an "edge")
+   */
   void EdgeAdded(NodeEdgePtr edge);
+
+  /**
+   * @brief Signal emitted when a member node of this graph has been disconnected from another (removing an "edge")
+   */
   void EdgeRemoved(NodeEdgePtr edge);
 
 private:
diff --git a/app/node/input.h b/app/node/input.h
index 952e3ed11..2c8f116c0 100644
--- a/app/node/input.h
+++ b/app/node/input.h
@@ -24,34 +24,102 @@
 #include "keyframe.h"
 #include "param.h"
 
+/**
+ * @brief A node parameter designed to take either user input or data from another node
+ */
 class NodeInput : public NodeParam
 {
 public:
   NodeInput();
 
+  /**
+   * @brief Returns kInput
+   */
   virtual Type type() override;
 
+  /**
+   * @brief Add a data type that this input accepts
+   *
+   * While an input will usually only accept one data type, NodeInput supports several. Use this to add a data type that
+   * this input can accept.
+   */
   void add_data_input(const DataType& data_type);
 
+  /**
+   * @brief Return whether an input can accept a certain type based on its list of data types
+   *
+   * The input checks its list of acceptable data types (added by add_data_input()) to determine whether a certain
+   * data type can be connected to this input.
+   */
   bool can_accept_type(const DataType& data_type);
 
+  /**
+   * @brief Return whether this parameter accepts multiple inputs (false by default)
+   *
+   * While an input will usually only accept one connection from an output at any given time, NodeInput does support
+   * more than one. By default this is false, but can be set to true on any input object. If this is true, get_value()
+   * returns QList<QVariant> rather than just a QVariant (but casted to QVariant).
+   */
   bool can_accept_multiple_inputs();
+
+  /**
+   * @brief \see can_accept_multiple_inputs().
+   */
   void set_can_accept_multiple_inputs(bool b);
 
+  /**
+   * @brief Get the value at a given time
+   *
+   * This function will automatically retrieve the correct value for this input at the given time.
+   *
+   * If an output is connected to this input, a request is made to that output for its value at this time. If multiple
+   * outputs are connected (\see can_accept_multiple_inputs()), a QList<QVariant> (casted to a QVariant) is returned
+   * instead, listing all the outputs' values currently connected.
+   *
+   * If no output is connected, this will return a user-defined value, either a static value if this input is not
+   * keyframed, or an interpolated value between the keyframes at this time.
+   */
   QVariant get_value(const rational &time);
 
+  /**
+   * @brief Return whether keyframing is enabled on this input or not
+   */
   bool keyframing();
+
+  /**
+   * @brief Set whether keyframing is enabled on this input or not
+   */
   void set_keyframing(bool k);
 
+  /**
+   * @brief A list of input data types accepted by this parameter
+   */
   const QList<DataType>& inputs();
 
 private:
+  /**
+   * @brief Internal list of accepted data types
+   *
+   * Use can_accept_type() to check if a type is in this list
+   */
   QList<DataType> inputs_;
 
+  /**
+   * @brief Internal keyframe array
+   *
+   * All internal/user-defined data is stored in this array. Even if keyframing is not enabled, this array will contain
+   * one entry which will be used, and its time value will be ignored.
+   */
   QList<NodeKeyframe> keyframes_;
 
+  /**
+   * @brief Internal keyframing enabled setting
+   */
   bool keyframing_;
 
+  /**
+   * @brief Internal multiple inputs accepted setting
+   */
   bool can_accept_multiple_inputs_;
 };
 
diff --git a/app/node/input/image/image.cpp b/app/node/input/image/image.cpp
index 9c8efb7f2..e82f30cc4 100644
--- a/app/node/input/image/image.cpp
+++ b/app/node/input/image/image.cpp
@@ -13,6 +13,11 @@ QString ImageInput::Name()
   return tr("Image");
 }
 
+QString ImageInput::id()
+{
+  return "org.olivevideoeditor.Olive.imageinput";
+}
+
 QString ImageInput::Category()
 {
   return tr("Input");
diff --git a/app/node/input/image/image.h b/app/node/input/image/image.h
index e64a541c8..b07e1734d 100644
--- a/app/node/input/image/image.h
+++ b/app/node/input/image/image.h
@@ -5,6 +5,12 @@
 
 #include "node/node.h"
 
+/**
+ * @brief A node that imports an image
+ *
+ * FIXME: This will likely be replaced by the Media node as the Media node will be set up to pull from various decoders
+ *        from the beginning.
+ */
 class ImageInput : public Node
 {
   Q_OBJECT
@@ -12,6 +18,7 @@ public:
   ImageInput();
 
   virtual QString Name() override;
+  virtual QString id() override;
   virtual QString Category() override;
   virtual QString Description() override;
 
diff --git a/app/node/keyframe.h b/app/node/keyframe.h
index e482bccfd..59dbe6be2 100644
--- a/app/node/keyframe.h
+++ b/app/node/keyframe.h
@@ -25,24 +25,42 @@
 
 #include "common/rational.h"
 
+/**
+ * @brief A point of data to be used at a certain time and interpolated with other data
+ */
 class NodeKeyframe
 {
 public:
 
+  /**
+   * @brief Methods of interpolation to use with this keyframe
+   */
   enum Type {
     kLinear,
     kHold,
     kBezier
   };
 
+  /**
+   * @brief NodeKeyframe Constructor
+   */
   NodeKeyframe();
 
+  /**
+   * @brief The time this keyframe is set at
+   */
   const rational& time();
   void set_time(const rational& time);
 
+  /**
+   * @brief The value of this keyframe (i.e. the value to use at this keyframe's time)
+   */
   const QVariant& value();
   void set_value(const QVariant &value);
 
+  /**
+   * @brief The method of interpolation to use with this keyframe
+   */
   const Type& type();
   void set_type(const Type& type);
 
diff --git a/app/node/node.h b/app/node/node.h
index e776255d5..766683786 100644
--- a/app/node/node.h
+++ b/app/node/node.h
@@ -27,16 +27,68 @@
 #include "node/input.h"
 #include "node/output.h"
 
+/**
+ * @brief A single processing unit that can be connected with others to create intricate processing systems
+ *
+ * A cornerstone of "visual programming", a node is a single "function" that takes input and returns an output that can
+ * be connected to other nodes. Inputs can be either user-set or retrieved from the output of another node. By joining
+ * several nodes together, intricate, highly customizable, and infinitely extensible systems can be made for processing
+ * data. It can also all be exposed to the user without forcing them to write code or compile anything.
+ *
+ * A major example in Olive is the entire rendering workflow. To render a frame, Olive will work through a node graph
+ * that can be infinitely customized by the user to create images.
+ *
+ * This is a simple base class designed to contain all the functionality for this kind of processing connective unit.
+ * It is an abstract class intended to be subclassed to create nodes with actual functionality.
+ */
 class Node : public QObject
 {
   Q_OBJECT
 public:
   Node();
 
+  /**
+   * @brief Return the name of the node
+   *
+   * This is the node's name shown to the user. This must be overridden by subclasses, and preferably run through the
+   * translator.
+   */
   virtual QString Name() = 0;
+
+  /**
+   * @brief Return the unique identifier of the node
+   *
+   * This is used in save files and any other times a specific node must be picked out at runtime. This must be an ID
+   * completely unique to this node, and preferably in bundle identifier format (e.g. "org.company.Name"). This string
+   * should NOT be translated.
+   */
+  virtual QString id() = 0;
+
+  /**
+   * @brief Return the category this node is in (optional for subclassing, but recommended)
+   *
+   * In any organized node menus, show the node in this category. If this node should be in a subfolder of a subfolder,
+   * use a "/" to separate categories (e.g. "Distort/Noise"). The string should not start with a "/" as this will be
+   * interpreted as an empty string category. This value should be run through a translator as its largely user
+   * oriented.
+   */
   virtual QString Category();
+
+  /**
+   * @brief Return a description of this node's purpose (optional for subclassing, but recommended)
+   *
+   * A short (1-2 sentence) description of what this node should do to help the user understand its purpose. This should
+   * be run through a translator.
+   */
   virtual QString Description();
 
+  /**
+   * @brief Add a parameter to this node
+   *
+   * The Node takes ownership of this parameter.
+   *
+   * This can be either an output or an input at any time. Parameters will always appear in the order they're added.
+   */
   void AddParameter(NodeParam* param);
 
   /**
@@ -72,10 +124,38 @@ public:
   int IndexOfParameter(NodeParam* param);
 
 public slots:
+  /**
+   * @brief The main processing function
+   *
+   * The node's main purpose is to take values from inputs to set values in outputs. For whatever subclass node you
+   * create, this is where the code for that goes.
+   *
+   * Note that as a video editor, the node graph has to work across time. Depending on the purpose of your node, it may
+   * output different values depending on the time, and even if not, it will likely be receiving different input
+   * depending on the time. Most of the difficult work here is handled by NodeInput::get_value() which you should pass
+   * the `time` parameter to. It will return its value (at that time, if it's keyframed), or pass the time to a
+   * corresponding output if it's connected to one. If your node doesn't directly deal with time, the default behavior
+   * of the NodeParam objects will handle everything related to it automatically.
+   */
   virtual void Process(const rational& time) = 0;
 
 signals:
+  /**
+   * @brief Signal emitted when a node is connected to another node (creating an "edge")
+   *
+   * @param edge
+   *
+   * The edge that was added
+   */
   void EdgeAdded(NodeEdgePtr edge);
+
+  /**
+   * @brief Signal emitted when a node is disconnected from another node (removing an "edge")
+   *
+   * @param edge
+   *
+   * The edge that was removed
+   */
   void EdgeRemoved(NodeEdgePtr edge);
 };
 
diff --git a/app/node/output.h b/app/node/output.h
index 8e2014ed8..a03574fd5 100644
--- a/app/node/output.h
+++ b/app/node/output.h
@@ -23,17 +23,52 @@
 
 #include "param.h"
 
+/**
+ * @brief A node parameter designed to serve data to the input of another node
+ */
 class NodeOutput : public NodeParam
 {
 public:
+  /**
+   * @brief NodeOutput Constructor
+   */
   NodeOutput();
 
+  /**
+   * @brief Returns kOutput
+   */
   virtual Type type() override;
 
+  /**
+   * @brief The data type this parameter outputs
+   *
+   * This can be used in conjunction with NodeInput::can_accept_type() to determine whether this parameter can be
+   * connected to it.
+   */
   const DataType& data_type();
   void set_data_type(const DataType& type);
 
+  /**
+   * @brief Get the value of this output at a given tie
+   *
+   * This function is intended to primarily be called by any connected NodeInputs.
+   *
+   * The first thing this function does is request the parent Node object to Process() at this time. The Node should
+   * then perform whatever actions necessary (usually taking data from inputs and creating output data) to set the
+   * correct value that this output should have at this time (the Node should use set_value() for this). This function
+   * will then return the value that was set after Process() returned.
+   *
+   * In many cases for efficiency, the Node can also ignore this request if it knows the output data will not change
+   * (i.e. if the time has not changed from the last Process()).
+   */
   virtual const QVariant& get_value(const rational &time);
+
+  /**
+   * @brief Set the current value of this output
+   *
+   * Intended to only be set by parent Node objects in their Node::Process() function. Whatever result data is intended
+   * for use later in the pipeline should be set here (\see get_value()).
+   */
   virtual void set_value(const QVariant& value);
 
 private:
diff --git a/app/node/output/viewer/viewer.cpp b/app/node/output/viewer/viewer.cpp
index 224ea6537..3b5b75299 100644
--- a/app/node/output/viewer/viewer.cpp
+++ b/app/node/output/viewer/viewer.cpp
@@ -15,6 +15,11 @@ QString ViewerOutput::Name()
   return tr("Viewer");
 }
 
+QString ViewerOutput::id()
+{
+  return "org.olivevideoeditor.Olive.vieweroutput";
+}
+
 QString ViewerOutput::Category()
 {
   return tr("Output");
diff --git a/app/node/output/viewer/viewer.h b/app/node/output/viewer/viewer.h
index f07dd4b6e..d219fa8ac 100644
--- a/app/node/output/viewer/viewer.h
+++ b/app/node/output/viewer/viewer.h
@@ -4,6 +4,11 @@
 #include "node/node.h"
 #include "panel/viewer/viewer.h"
 
+/**
+ * @brief A bridge between a node system and a ViewerPanel
+ *
+ * Receives update/time change signals from ViewerPanels and responds by sending them a texture of that frame
+ */
 class ViewerOutput : public Node
 {
   Q_OBJECT
@@ -11,6 +16,7 @@ public:
   ViewerOutput();
 
   virtual QString Name() override;
+  virtual QString id() override;
   virtual QString Category() override;
   virtual QString Description() override;
 
diff --git a/app/node/param.cpp b/app/node/param.cpp
index 553b978ad..4f5939325 100644
--- a/app/node/param.cpp
+++ b/app/node/param.cpp
@@ -113,7 +113,7 @@ bool NodeParam::AreDataTypesCompatible(const DataType &output_type, const QList<
 NodeEdgePtr NodeParam::ConnectEdge(NodeOutput *output, NodeInput *input)
 {
   // If the input can only accept one input (the default) and has one already, disconnect it
-  FreeSpaceForEdgeFromInput(input);
+  DisconnectForNewOutput(input);
 
   // Make sure it's not a duplicate of an edge that already exists
   foreach (NodeEdgePtr existing, input->edges()) {
@@ -155,7 +155,7 @@ void NodeParam::DisconnectEdge(NodeOutput *output, NodeInput *input)
   }
 }
 
-NodeEdgePtr NodeParam::FreeSpaceForEdgeFromInput(NodeInput *input)
+NodeEdgePtr NodeParam::DisconnectForNewOutput(NodeInput *input)
 {
   // If the input can only accept one input (the default) and has one already, disconnect it
   if (!input->edges_.isEmpty() && !input->can_accept_multiple_inputs()) {
diff --git a/app/node/param.h b/app/node/param.h
index 7ae269af8..7d83aef01 100644
--- a/app/node/param.h
+++ b/app/node/param.h
@@ -29,15 +29,29 @@
 
 class Node;
 
+/**
+ * @brief A base parameter of a Node
+ *
+ * The main data points of a Node. NodeParams are added to Nodes so that Node::Process() can use data acquired either
+ * directly as a value set by the user, or through the output of another NodeParam.
+ *
+ * This is an abstract base class. In most cases you'll want NodeInput or NodeOutput.
+ */
 class NodeParam : public QObject
 {
   Q_OBJECT
 public:
+  /**
+   * @brief The type of parameter this is
+   */
   enum Type {
     kInput,
     kOutput
   };
 
+  /**
+   * @brief The types of data that can be passed between Nodes
+   */
   enum DataType {
     kNone,
     kInt,
@@ -53,40 +67,155 @@ public:
     kAny
   };
 
+  /**
+   * @brief NodeParam Constructor
+   */
   NodeParam();
 
+  /**
+   * @brief The type of node paramter this is
+   *
+   * This must be set in subclasses, but most of the time you should probably subclass from NodeInput and NodeOutput
+   * anyway.
+   */
   virtual Type type() = 0;
 
+  /**
+   * @brief Name of this parameter to be shown to the user
+   */
   const QString& name();
   void set_name(const QString& name);
 
+  /**
+   * @brief Node parent object
+   *
+   * Nodes and NodeParams use the QObject parent-child system. This function is a convenience function for
+   * static_cast<Node*>(QObject::parent())
+   */
   Node* parent();
 
+  /**
+   * @brief Return the row index of this parameter in the parent node (primarily used for UI drawing functions)
+   */
   int index();
 
+  /**
+   * @brief Return a list of edges (aka connections to other nodes)
+   *
+   * This list can't be modified directly. Use ConnectEdge() and DisconnectEdge() instead for that.
+   */
   const QVector<NodeEdgePtr>& edges();
 
-  static bool AreDataTypesCompatible(NodeParam* a, NodeParam* b);
+  /**
+   * @brief Determine whether two DataTypes are compatible and therefore whether two NodeParams can be connected
+   *
+   * Obviously a data type is compatible with itself, but sometimes fundamentally separate data types may still be
+   * allowed to connect (e.g. an integer output to a float input). This static function should be used to determine
+   * whether a data type is compatible with another.
+   */
   static bool AreDataTypesCompatible(const DataType& output_type, const DataType& input_type);
+
+  /**
+   * @brief Overload of AreDataTypesCompatible(const DataType& output_type, const DataType& input_type)
+   *
+   * Use this for a list of input data types (which NodeInput uses as it's possible for it to accept multiple types).
+   */
   static bool AreDataTypesCompatible(const DataType& output_type, const QList<DataType>& input_types);
 
+  /**
+   * @brief Overload of AreDataTypesCompatible(const DataType& output_type, const DataType& input_type)
+   *
+   * Convenience function for two NodeParams. Determines which is the input/output and determines whether their types
+   * are compatible.
+   */
+  static bool AreDataTypesCompatible(NodeParam* a, NodeParam* b);
+
+  /**
+   * @brief Connect an output parameter to an input parameter
+   *
+   * This function makes no attempt to check whether the two NodeParams have compatible data types. This should be done
+   * beforehand or behavior is undefined.
+   *
+   * If the input already has an edge connected and can't accept multiple edges, that edge is disconnected before an
+   * attempt at a new connection is made. This function returns the new NodeEdge created by this connection.
+   *
+   * If the input *can* accept multiple edges but is already connected to this output, no new connection is made (since
+   * the connection already exists). In this situation, nullptr is returned.
+   *
+   * This function emits EdgeAdded().
+   */
   static NodeEdgePtr ConnectEdge(NodeOutput *output, NodeInput *input);
+
+  /**
+   * @brief Disconnect an edge
+   *
+   * This function emits EdgeRemoved(NodeEdgePtr edge).
+   *
+   * @param edge
+   *
+   * Edge to disconnect.
+   */
   static void DisconnectEdge(NodeEdgePtr edge);
+
+  /**
+   * @brief Disconnect an edge
+   *
+   * Sometimes this function is preferable if you don't know what the edge object is (or with undo commands where the
+   * edge object may change despite the connection being between the same parameters).
+   *
+   * This function emits EdgeRemoved(NodeEdgePtr edge).
+   *
+   * @param edge
+   *
+   * Edge to disconnect.
+   */
   static void DisconnectEdge(NodeOutput* output, NodeInput* input);
 
-  static NodeEdgePtr FreeSpaceForEdgeFromInput(NodeInput* input);
+  /**
+   * @brief If an input has an edge and can't take multiple, this function disconnects them and returns the edge object
+   *
+   * This is used just before a connection is about to be made. If an input is already connected to an output, but
+   * can't take multiple inputs, that connection will need to be removed before the new connection can be made.
+   * This function check if it's necessary to remove the edge from an input before connecting a new edge, and removes
+   * and returns it if so.
+   *
+   * If the input does NOT have anything connected, or it does but the input CAN accept multiple connections, nothing
+   * is disconnected and nullptr is returned.
+   */
+  static NodeEdgePtr DisconnectForNewOutput(NodeInput* input);
 
+  /**
+   * @brief Get a human-readable translated name for a certain data type
+   */
   static QString GetDefaultDataTypeName(const DataType &type);
 
 signals:
+  /**
+   * @brief Signal emitted when an edge is added to this parameter
+   *
+   * See ConnectEdge() for usage. Only one of the two parameters needs to emit this signal when a connection is made,
+   * because otherwise two of exactly the same signal will be emitted.
+   */
   void EdgeAdded(NodeEdgePtr edge);
+
+  /**
+   * @brief Signal emitted when an edge is removed from this parameter
+   *
+   * See DisconnectEdge() for usage. Only one of the two parameters needs to emit this signal when a connection is
+   * removed, because otherwise two of exactly the same signal will be emitted.
+   */
   void EdgeRemoved(NodeEdgePtr edge);
 
 protected:
+  /**
+   * @brief Internal list of edges
+   */
   QVector<NodeEdgePtr> edges_;
 
 private:
-
+  /**
+   * @brief Internal name string
+   */
   QString name_;
 
 };
diff --git a/app/node/processor/renderer/renderer.h b/app/node/processor/renderer/renderer.h
index 4ccd050ff..6285c22cf 100644
--- a/app/node/processor/renderer/renderer.h
+++ b/app/node/processor/renderer/renderer.h
@@ -24,6 +24,9 @@
 #include "node/node.h"
 #include "rendererthread.h"
 
+/**
+ * @brief A multithreaded OpenGL based renderer for node systems
+ */
 class RendererProcessor : public Node
 {
   Q_OBJECT
diff --git a/app/widget/nodeview/nodeviewundo.cpp b/app/widget/nodeview/nodeviewundo.cpp
index 9836bc97a..4e61e422a 100644
--- a/app/widget/nodeview/nodeviewundo.cpp
+++ b/app/widget/nodeview/nodeviewundo.cpp
@@ -15,7 +15,7 @@ void NodeEdgeAddCommand::redo()
     return;
   }
 
-  old_edge_ = NodeParam::FreeSpaceForEdgeFromInput(input_);
+  old_edge_ = NodeParam::DisconnectForNewOutput(input_);
 
   NodeParam::ConnectEdge(output_, input_);