diff --git a/src/EscapeSequenceParser.test.ts b/src/EscapeSequenceParser.test.ts
index 01e018ef..2d85c466 100644
--- a/src/EscapeSequenceParser.test.ts
+++ b/src/EscapeSequenceParser.test.ts
@@ -1239,5 +1239,5 @@ describe('EscapeSequenceParser', function (): void {
       chai.expect(errorState).eql(null);
     });
   });
-  // TODO: error conditions
+  // TODO: error conditions and error recovery (not implemented yet in parser)
 });
diff --git a/src/EscapeSequenceParser.ts b/src/EscapeSequenceParser.ts
index 207c32e9..7e71e8b5 100644
--- a/src/EscapeSequenceParser.ts
+++ b/src/EscapeSequenceParser.ts
@@ -205,6 +205,7 @@ class DcsDummy implements IDcsHandler {
  * the optional `transitions` contructor argument and
  * reimplement the `parse` method.
  * NOTE: The parameter element notation is currently not supported.
+ * TODO: implement error recovery hook via error handler return values
  */
 export class EscapeSequenceParser implements IEscapeSequenceParser {
   public initialState: number;
@@ -433,7 +434,7 @@ export class EscapeSequenceParser implements IEscapeSequenceParser {
                 abort: false
               });
             if (inject.abort) return;
-          // FIXME: inject return values
+          // TODO: inject return values
             error = false;
           }
           break;
@@ -500,7 +501,10 @@ export class EscapeSequenceParser implements IEscapeSequenceParser {
             if (idx === -1) {
               this._oscHandlerFb(-1, osc);  // this is an error (malformed OSC)
             } else {
-              let identifier = parseInt(osc.substring(0, idx)); // NaN not handled here
+              // Note: NaN is not handled here
+              // either catch it with the fallback handler
+              // or with an explicit NaN OSC handler
+              let identifier = parseInt(osc.substring(0, idx));
               let content = osc.substring(idx + 1);
               callback = this._oscHandlers[identifier];
               if (callback) callback(content);
diff --git a/src/InputHandler.ts b/src/InputHandler.ts
index 397ec984..16571c66 100644
--- a/src/InputHandler.ts
+++ b/src/InputHandler.ts
@@ -51,14 +51,18 @@ class RequestTerminfo implements IDcsHandler {
  */
 class DECRQSS implements IDcsHandler {
   private _data: string;
+
   constructor(private _terminal: any) { }
+
   hook(collect: string, params: number[], flag: number): void {
     // reset data
     this._data = '';
   }
+
   put(data: string, start: number, end: number): void {
     this._data += data.substring(start, end);
   }
+
   unhook(): void {
     switch (this._data) {
       // valid: DCS 1 $ r Pt ST (xterm)
@@ -71,7 +75,7 @@ class DECRQSS implements IDcsHandler {
                 ';' + (this._terminal.buffer.scrollBottom + 1) + 'r';
         return this._terminal.send(C0.ESC + 'P1' + '$r' + pt + C0.ESC + '\\');
       case 'm': // SGR
-        // FIXME: report real settings instead of 0m
+        // TODO: report real settings instead of 0m
         return this._terminal.send(C0.ESC + 'P1' + '$r' + '0m' + C0.ESC + '\\');
       case ' q': // DECSCUSR
         const STYLES = {'block': 2, 'underline': 4, 'bar': 6};
@@ -189,8 +193,7 @@ export class InputHandler implements IInputHandler {
     this._parser.setExecuteHandler(C0.HT, () => this.tab());
     this._parser.setExecuteHandler(C0.SO, () => this.shiftOut());
     this._parser.setExecuteHandler(C0.SI, () => this.shiftIn());
-    // FIXME:   What do to with missing? Old code just added those to print, but that's wrong
-    //          behavior for most control codes.
+    // FIXME:   What do to with missing? Old code just added those to print.
 
     // some C1 control codes - FIXME: should those be enabled by default?
     this._parser.setExecuteHandler(C1.IND, () => this.index());
@@ -264,7 +267,7 @@ export class InputHandler implements IInputHandler {
       this._parser.setEscHandler('+' + flag, () => this.selectCharset('+' + flag));
       this._parser.setEscHandler('-' + flag, () => this.selectCharset('-' + flag));
       this._parser.setEscHandler('.' + flag, () => this.selectCharset('.' + flag));
-      this._parser.setEscHandler('/' + flag, () => this.selectCharset('/' + flag)); // FIXME: supported?
+      this._parser.setEscHandler('/' + flag, () => this.selectCharset('/' + flag)); // TODO: supported?
     }
 
     /**
@@ -1889,7 +1892,7 @@ export class InputHandler implements IInputHandler {
    */
   public selectCharset(collectAndFlag: string): void {
     if (collectAndFlag.length !== 2) return this.selectDefaultCharset();
-    if (collectAndFlag[0] === '/') return;  // FIXME: Is this supported?
+    if (collectAndFlag[0] === '/') return;  // TODO: Is this supported?
     this._terminal.setgCharset(GLEVEL[collectAndFlag[0]], CHARSETS[collectAndFlag[1]] || DEFAULT_CHARSET);
   }
 
@@ -1900,7 +1903,7 @@ export class InputHandler implements IInputHandler {
    *   Moves the cursor down one line in the same column.
    */
   public index(): void {
-    this._terminal.index();  // FIXME: save to move the implementation from terminal?
+    this._terminal.index();  // TODO: save to move from terminal?
   }
 
   /**
@@ -1911,7 +1914,7 @@ export class InputHandler implements IInputHandler {
    *   the value of the active column when the terminal receives an HTS.
    */
   public tabSet(): void {
-    this._terminal.tabSet();  // FIXME: save to move the implementation from terminal?
+    this._terminal.tabSet();  // TODO: save to move from terminal?
   }
 
   /**
@@ -1922,7 +1925,7 @@ export class InputHandler implements IInputHandler {
    *   the page scrolls down.
    */
   public reverseIndex(): void {
-    this._terminal.reverseIndex();  // FIXME: save to move the implementation from terminal?
+    this._terminal.reverseIndex();  // TODO: save to move from terminal?
   }
 
   /**
@@ -1931,7 +1934,8 @@ export class InputHandler implements IInputHandler {
    *   Reset to initial state.
    */
   public reset(): void {
-    this._terminal.reset();  // FIXME: save to move the implementation from terminal?
+    this._parser.reset();
+    this._terminal.reset();  // TODO: save to move from terminal?
   }
 
   /**
@@ -1945,6 +1949,6 @@ export class InputHandler implements IInputHandler {
    *   you use another locking shift. (partly supported)
    */
   public setgLevel(level: number): void {
-    this._terminal.setgLevel(level);  // FIXME: save to move the implementation from terminal?
+    this._terminal.setgLevel(level);  // TODO: save to move from terminal?
   }
 }
diff --git a/src/Types.ts b/src/Types.ts
index 52812e3d..b1aced5c 100644
--- a/src/Types.ts
+++ b/src/Types.ts
@@ -422,7 +422,7 @@ export const enum ParserAction {
 
 /**
  * Internal state of EscapeSequenceParser.
- * Used as argument to the error handler to allow
+ * Used as argument of the error handler to allow
  * introspection at runtime on parse errors.
  * Return it with altered values to recover from
  * faulty states (not yet supported).