diff --git a/README.md b/README.md
index 437116a..acb2920 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ Testing is done with mocha and can be executed using `npm test`.
 
 ## General structure
 
-[index.ts](./src/index.ts) is exectued when starting the server. It includes all setup tasks, registers middleware,
+[index.ts](./src/index.ts) is executed when starting the server. It includes all setup tasks, registers middleware,
 routes and error handlers. Setting the `NODE_ENV` environment variable allows starting the server either in 
 `production`, `development` or `test` mode.
 
diff --git a/src/db.ts b/src/db.ts
index f41cee3..b82151d 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -149,7 +149,6 @@ export default class db {
   // changelog entry, expects (req, this (from query helper)) or (req, collection, conditions, data)
   static log(req, thisOrCollection, conditions = null, data = null) {
     if (! (conditions || data)) {  // (req, this)
-      console.log(11);
       data = thisOrCollection._update ? _.cloneDeep(thisOrCollection._update) : {};  // replace undefined with {}
       // replace keys with a leading $
       Object.keys(data).forEach(key => {
@@ -158,7 +157,6 @@ export default class db {
           delete data[key];
         }
       });
-      console.log(thisOrCollection._conditions);
       new ChangelogModel(this.logEscape(_.cloneDeep({
         action: req.method + ' ' + req.url,
         collection_name: thisOrCollection._collection.collectionName,
diff --git a/src/helpers/csv.ts b/src/helpers/csv.ts
index d7774d7..5e8ae03 100644
--- a/src/helpers/csv.ts
+++ b/src/helpers/csv.ts
@@ -1,7 +1,7 @@
 import {parseAsync} from 'json2csv';
 import flatten from './flatten';
 
-export default function csv(input: any[], f: (err, data) => void) {
+export default function csv(input: any[], f: (err, data) => void) {  // parse JSON to CSV
   parseAsync(input.map(e => flatten(e)), {includeEmptyRows: true})
     .then(csv => f(null, csv))
     .catch(err => f(err, null));
diff --git a/src/helpers/flatten.ts b/src/helpers/flatten.ts
index ed54da9..d28bd64 100644
--- a/src/helpers/flatten.ts
+++ b/src/helpers/flatten.ts
@@ -3,10 +3,10 @@ import globals from '../globals';
 export default function flatten (data, keepArray = false) {  // flatten object: {a: {b: true}} -> {a.b: true}
   const result = {};
   function recurse (cur, prop) {
-    if (Object(cur) !== cur || Object.keys(cur).length === 0) {
+    if (Object(cur) !== cur || Object.keys(cur).length === 0) {  // simple value
       result[prop] = cur;
     }
-    else if (prop === `${globals.spectrum.spectrum}.${globals.spectrum.dpt}`) {
+    else if (prop === `${globals.spectrum.spectrum}.${globals.spectrum.dpt}`) {  // convert spectrum for ML
       result[prop + '.labels'] = cur.map(e => parseFloat(e[0]));
       result[prop + '.values'] = cur.map(e => parseFloat(e[1]));
     }
@@ -27,7 +27,7 @@ export default function flatten (data, keepArray = false) {  // flatten object:
         }
       }
     }
-    else {
+    else {  // object
       let isEmpty = true;
       for (let p in cur) {
         isEmpty = false;
diff --git a/src/helpers/mail.ts b/src/helpers/mail.ts
index a76b287..2c0ab57 100644
--- a/src/helpers/mail.ts
+++ b/src/helpers/mail.ts
@@ -4,10 +4,10 @@ import axios from 'axios';
 
 export default class Mail{
 
-  static readonly address = 'definma@bosch-iot.com';
-  static uri: string;
-  static auth = {username: '', password: ''};
-  static mailPass: string;
+  static readonly address = 'definma@bosch-iot.com';  // email address
+  static uri: string;                                 // mail API URI
+  static auth = {username: '', password: ''};         // mail API credentials
+  static mailPass: string;                            // mail API generates password
 
   static init() {
     if (process.env.NODE_ENV === 'production') {  // only send mails in production
@@ -51,14 +51,14 @@ export default class Mail{
       }).then(() => {  // init done successfully
         console.info('Mail service established successfully');
         this.send('lukas.veit@bosch.com', 'Mail Service started', new Date().toString());
-      }).catch(err => {  // anywhere an error occurred
+      }).catch(err => {  // somewhere an error occurred
         console.error(`Mail init error: ${err.request.method} ${err.request.path}: ${err.response.status}`,
           err.response.data);
       });
     }
   }
 
-  static send (mailAddress, subject, content, f: (x?) => void = () => {}) {  // callback, executed empty or with error
+  static send (mailAddress, subject, content, f: (x?) => void = () => {}) {  // callback executed empty or with error
     if (process.env.NODE_ENV === 'production') {  // only send mails in production
       axios({
         method: 'post',
diff --git a/src/index.ts b/src/index.ts
index a2165e9..f64e847 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -100,6 +100,9 @@ app.use(require('./helpers/authorize'));  // handle authentication
 // redirect /api routes for Angular proxy in development
 if (process.env.NODE_ENV !== 'production') {
   app.use('/api/:url([^]+)', (req, res) => {
+    if (/help\//.test(req.params.url)) { // encode URI again for help route
+      req.params.url = 'help/' + encodeURIComponent(req.params.url.replace('help/', ''));
+    }
     req.url = '/' + req.params.url;
     app.handle(req, res);
   });
diff --git a/src/routes/material.ts b/src/routes/material.ts
index a75f73d..3996e30 100644
--- a/src/routes/material.ts
+++ b/src/routes/material.ts
@@ -25,21 +25,7 @@ router.get('/materials', (req, res, next) => {
     MaterialValidate.query(req.query, ['dev', 'admin'].indexOf(req.authDetails.level) >= 0);
   if (error) return res400(error, res);
 
-  let conditions;
-
-  if (filters.hasOwnProperty('status')) {
-    if(filters.status === 'all') {
-      conditions = {$or: [{status: globals.status.val}, {status: globals.status.new}]}
-    }
-    else {
-      conditions = {status: filters.status};
-    }
-  }
-  else {  // default
-    conditions = {status: globals.status.val};
-  }
-
-  MaterialModel.find(conditions).sort({name: 1}).populate('group_id').populate('supplier_id')
+  MaterialModel.find(filters).sort({name: 1}).populate('group_id').populate('supplier_id')
     .lean().exec((err, data) => {
     if (err) return next(err);
 
diff --git a/src/routes/sample.ts b/src/routes/sample.ts
index d5bc207..71e84e9 100644
--- a/src/routes/sample.ts
+++ b/src/routes/sample.ts
@@ -22,16 +22,12 @@ import globals from '../globals';
 
 const router = express.Router();
 
-// TODO: do not use streaming for spectrum filenames
-
 
 router.get('/samples', async (req, res, next) => {
   if (!req.auth(res, ['read', 'write', 'dev', 'admin'], 'all')) return;
 
   const {error, value: filters} = SampleValidate.query(req.query, ['dev', 'admin'].indexOf(req.authDetails.level) >= 0);
-  console.log(error);
   if (error) return res400(error, res);
-  console.log(filters.filters);
 
   // spectral data and csv not allowed for read/write users
   if ((filters.fields.find(e => e.indexOf('.' + globals.spectrum.dpt) >= 0) || filters.output !== 'json') &&
@@ -388,7 +384,6 @@ router.get('/samples', async (req, res, next) => {
     projection._id = false;
   }
   queryPtr.push({$project: projection});
-  console.log(JSON.stringify(query));
   // use streaming when including spectrum files
   if (!fieldsToAdd.find(e => e.indexOf(globals.spectrum.spectrum + '.' + globals.spectrum.dpt) >= 0)) {
     collection.aggregate(query).allowDiskUse(true).exec((err, data) => {
@@ -687,8 +682,6 @@ async function numberGenerate (sample, req, res, next) {
   const sampleData = await SampleModel
     .aggregate([
       {$match: {number: new RegExp('^' + req.authDetails.location + '[0-9]+$', 'm')}},
-      // {$addFields: {number2: {$toDecimal: {$arrayElemAt: [{$split: [{$arrayElemAt:
-      //   [{$split: ['$number', 'Rng']}, 1]}, '_']}, 0]}}}},  // not working with MongoDb 3.6
       {$addFields: {sortNumber: {$let: {
         vars: {tmp: {$concat: ['000000000000000000000000000000',
               {$arrayElemAt: [{$split:
@@ -701,7 +694,6 @@ async function numberGenerate (sample, req, res, next) {
     .exec()
     .catch(err => next(err));
   if (sampleData instanceof Error) return false;
-  console.log(sampleData);
   let number = (sampleData[0] ? Number(sampleData[0].number.replace(/[^0-9]+/g, '')) : 0);
   if (numberBuffer[req.authDetails.location] && numberBuffer[req.authDetails.location] >= number) {
     number = numberBuffer[req.authDetails.location];
diff --git a/src/routes/template.ts b/src/routes/template.ts
index d569bd2..8eeffdd 100644
--- a/src/routes/template.ts
+++ b/src/routes/template.ts
@@ -64,8 +64,6 @@ router.put('/template/:collection(measurement|condition|material)/' + IdValidate
   }
 
   if (!_.isEqual(_.pick(templateData, _.keys(template)), template)) {  // data was changed
-    console.log(template);
-    console.log(templateData);
     if (!template.parameters || _.isEqual(templateData.parameters, template.parameters)) {  // only name was changed
       model(req).findByIdAndUpdate(req.params.id, {name: template.name}, {new: true})
         .log(req).lean().exec((err, data) => {
diff --git a/src/routes/validate/sample.ts b/src/routes/validate/sample.ts
index 0d50576..efaedf1 100644
--- a/src/routes/validate/sample.ts
+++ b/src/routes/validate/sample.ts
@@ -199,7 +199,6 @@ export default class SampleValidate {
             data.filters[i] = decodeURIComponent(data.filters[i]);
           }
           catch (ignore) {}
-          console.log(data.filters[i]);
           data.filters[i] = JSON.parse(data.filters[i]);
           data.filters[i].values = data.filters[i].values.map(e => {  // validate filter values
             if (e === null) {  // null values are always allowed
@@ -241,7 +240,6 @@ export default class SampleValidate {
               validator = Joi.object(this.sample);
             }
             const {value, error} = validator.validate({[field]: e});
-            console.log(error);
             if (error) throw error;  // reject invalid values
             return value[field];
           });
diff --git a/src/routes/validate/user.ts b/src/routes/validate/user.ts
index 4ac78d4..c9288d7 100644
--- a/src/routes/validate/user.ts
+++ b/src/routes/validate/user.ts
@@ -75,7 +75,7 @@ export default class UserValidate {  // validate input for user
       }).validate(data);
     }
     else {
-      return{error: 'No parameter specified!', value: {}};
+      return {error: 'No parameter specified!', value: {}};
     }
   }