diff --git a/include/class-Category.php b/include/class-Category.php
new file mode 100644
index 0000000..7d3fbd1
--- /dev/null
+++ b/include/class-Category.php
@@ -0,0 +1,187 @@
+<?php
+# Copyright (C) 2020 Valerio Bozzolan
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Describes a Cronos Calendar Category
+ */
+class Category {
+
+	/**
+	 * Category UID
+	 */
+	private $uid;
+
+	/**
+	 * Category name
+	 */
+	private $name;
+
+	/**
+	 * Category filename on Wikimedia Commons without File: prefix
+	 */
+	private $filename;
+
+	/**
+	 * URL in sprintf format
+	 *
+	 * The %d argument can be replaced with the width in pixels.
+	 */
+	private $urlFormat;
+
+	/**
+	 * All the known categories
+	 */
+	private static $all = [];
+
+	/**
+	 * All the known aliases
+	 *
+	 * Associative array of starting Category UID and destination Category UID
+	 */
+	private static $aliases = [];
+
+	/**
+	 * Costructor
+	 *
+	 * @param string $uid User identifier
+	 * @param string $name Category name
+	 * @param string $filename File name on Wikimedia Commons
+	 * @param string $url_format URL in sprintf format with '%d' that can be sobstituted with the width in pixels
+	 */
+	public function __construct( $uid, $name, $filename, $url_format ) {
+		$this->uid = $uid;
+		$this->name = $name;
+		$this->filename = $filename;
+		$this->urlFormat = $url_format;
+	}
+
+	/**
+	 * Get the Category UID
+	 *
+	 * @return string
+	 */
+	public function getUID() {
+		return $this->uid;
+	}
+
+	/**
+	 * Get the Category Name
+	 *
+	 * @return string
+	 */
+	public function getName() {
+		return $this->name;
+	}
+
+	/**
+	 * Get the Category filename
+	 *
+	 * @return string
+	 */
+	public function getFilename() {
+		return $this->filename;
+	}
+
+	/**
+	 * Get Commons URL
+	 *
+	 * @return string
+	 */
+	public function getCommonsURL() {
+		return sprintf(
+			'https://commons.wikimedia.org/wiki/%s',
+			str_replace( ' ', '_', $this->filename )
+		);
+	}
+
+	/**
+	 * Get the image URL
+	 *
+	 * @param $size int You can set the width in pixels
+	 * @return string
+	 */
+	public function getImageURL( $size = 64 ) {
+		return sprintf(
+			$this->urlFormat,
+			$size
+		);
+	}
+
+	/**
+	 * Add a new Category
+	 *
+	 * @param string $uid User identifier
+	 * @param string $name Category name
+	 * @param string $filename File name on Wikimedia Commons
+	 * @param string $url_format URL in sprintf format with '%d' that can be sobstituted with the width in pixels
+	 */
+	public static function add( $uid, $name, $filename, $url_format ) {
+		self::$all[ $uid ] = new self( $uid, $name, $filename, $url_format );
+	}
+
+	/**
+	 * Add a new Category about "Bla bla initiatives"
+	 *
+	 * @param string $uid User identifier
+	 * @param string $name Category name
+	 * @param string $filename File name on Wikimedia Commons
+	 * @param string $url_format URL in sprintf format with '%d' that can be sobstituted with the width in pixels
+	 */
+	public static function addInitiatives( $uid, $name, $filename, $url_format ) {
+
+		// from 'bla bla'
+		// to 'bla bla initiatives'
+		$name = sprintf(
+			__( "%s initiatives" ),
+			$name
+		);
+
+		self::add( $uid, $name, $filename, $url_format );
+	}
+
+	/**
+	 * Add a Category alias
+	 *
+	 * @param $from string Category UID to start from
+	 * @param $to   string Category UID to start to
+	 */
+	public static function addAliasFromTO( $from, $to ) {
+		self::$aliases[ $from ] = $to;
+	}
+
+	/**
+	 * Get all the known categories
+	 *
+	 * @return array
+	 */
+	public static function all() {
+		return self::$all;
+	}
+
+	/**
+	 * Find a Category by UID
+	 *
+	 * @return Category|false
+	 */
+	public static function find( $uid ) {
+
+		// eventually replace with its existing alias
+		$uid = self::$aliases[ $uid ] ?? $uid;
+
+		// return the existing Category or false
+		return self::$all[ $uid ] ?? false;
+	}
+}
diff --git a/include/class-CronosHomepage.php b/include/class-CronosHomepage.php
index ca98288..e6df2a3 100644
--- a/include/class-CronosHomepage.php
+++ b/include/class-CronosHomepage.php
@@ -1,424 +1,426 @@
 <?php
 # Copyright (C) 2020 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 // OAuth PHP library stuff
 use MediaWiki\OAuthClient\ClientConfig;
 use MediaWiki\OAuthClient\Consumer;
 use MediaWiki\OAuthClient\Client;
 use MediaWiki\OAuthClient\Token;
 
 // boz-mw stuff
 use web\MediaWikis;
 
 // various cookies
 // we use cookies instead of PHP sessions because in this way the application is stateless
 // moreover, Wikimedia Toolforge's NFS storage is not that quick :^)
 define( 'COOKIE_OAUTH_REQUEST_TOKEN_KEY',    'oa_rqtk_key'       );
 define( 'COOKIE_OAUTH_REQUEST_TOKEN_SECRET', 'oa_rqtk_sec'       );
 define( 'COOKIE_OAUTH_ACCESS_TOKEN_KEY',     'oa_accsstk_key'    );
 define( 'COOKIE_OAUTH_ACCESS_TOKEN_SECRET',  'oa_accsstk_secret' );
 define( 'COOKIE_OAUTH_ACCESS_NONCE',         'oa_accss_nnc'      );
 define( 'COOKIE_WIKI_USERNAME',              'wiki_user'         );
 define( 'COOKIE_WIKI_CSRF',                  'wiki_csrf'         );
 
 class CronosHomepage {
 
 	/**
 	 * Check if the user has submitted the form
 	 */
 	private $saved = false;
 
 	/**
 	 * OAuth client
 	 */
 	private $client;
 
 	/**
 	 * Access token
 	 */
 	private $accessToken;
 
 	/**
 	 * The wiki API URL
 	 *
 	 * @var string
 	 */
 	private $wikiApi = 'https://meta.wikimedia.org/w/api.php';
 
 	/**
 	 * Submitted form data
 	 */
 	private $post = [];
 
 	/**
 	 * Title of the events page of the current date
 	 */
 	private $eventsPageTitle;
 
 	/**
 	 * Constructor
 	 */
 	public function __construct() {
 
 		// OAuth configuration
 		// see oauthclient-php
 		$conf = new ClientConfig( 'https://meta.wikimedia.org/w/index.php?title=Special:OAuth' );
 		$conf->setConsumer( new Consumer( OAUTH_CONSUMER_KEY, OAUTH_CONSUMER_SECRET ) );
 		$this->client = new Client( $conf );
 
 		// Wikimedia Commons API
 		// see boz-mw
 		$commons = MediaWikis::findFromUID( 'commonswiki' );
 
 		$events_page_title = null;
 
 		// Phase 1
 		// check if the user submitted the login form and have to be redirected to the remote OAuth login form
 		if( is_action( 'login' ) ) {
 
 			$this->tryOAuthLogin();
 		}
 
 		// check if the user wants to logout
 		if( is_action( 'logout' ) ) {
 
 			$this->logout();
 
 		}
 
 		// Phase 2
 		// check if the user is coming back from the remote OAuth login form
 		if( isset( $_GET['oauth_verifier'] ) ) {
 
 			$this->receiveOAuthResponse();
 
 		}
 
 		// prepare the OAuth access token
 		$this->prepareOAuthAccessToken();
 
 		// Phase 3: save
 		if( $this->accessToken && is_action( 'create-event' ) ) {
 
 			$this->createEvent();
 		}
 	}
 
 	public function isEventsPageTitleKnown() {
 		return isset( $this->eventsPageTitle );
 	}
 
 	public function getEventsPageTitle() {
 		return $this->eventsPageTitle;
 	}
 
 	public function getEventsPageURL() {
 		return sprintf(
 			'https://meta.wikimedia.org/wiki/%s',
 			urlencode( $this->getEventsPageTitle() )
 		);
 	}
 
 	public function hasSaved() {
 		return $this->saved;
 	}
 
 	public function isUserUnknown() {
 		return empty( $_COOKIE[ COOKIE_WIKI_USERNAME ] );
 	}
 
 	public function getAnnouncedUsername() {
 		return $_COOKIE[ COOKIE_WIKI_USERNAME ] ?? null;
 	}
 
 	/**
 	 * Print the website header
 	 */
 	public function printHeader() {
 
 		enqueue_js( 'cronos' );
 
 		template( 'header' );
 
 	}
 
 	/**
 	 * Print the website footer
 	 */
 	public function printFooter() {
 
 		template( 'footer' );
 
 	}
 
 	/**
 	 * Get a submitted information
 	 *
 	 * @param string $key
 	 * @param string $default_value
 	 */
 	public function getPOST( $key, $default_value = null ) {
 
 		// eventually receive submitted data
 		if( !array_key_exists( $key, $this->post ) ) {
 
 			// technically it's possible to submit arrays (asd[]=1) so let's clean
-			if( is_string( $_POST[ $key ] ) ) {
+			if( isset( $_POST[ $key ] ) && is_string( $_POST[ $key ] ) ) {
 				$this->post[ $key ] = $_POST[ $key ];
 			}
 		}
 
 		return $this->post[ $key ] ?? $default_value;
 	}
 
 	/**
 	 * Forget this OAuth session
 	 */
 	private function logout() {
 
 		// clear all cookies
 		my_unset_cookie( COOKIE_OAUTH_REQUEST_TOKEN_KEY );
 		my_unset_cookie( COOKIE_OAUTH_REQUEST_TOKEN_SECRET );
 		my_unset_cookie( COOKIE_OAUTH_ACCESS_TOKEN_KEY );
 		my_unset_cookie( COOKIE_OAUTH_ACCESS_TOKEN_SECRET );
 		my_unset_cookie( COOKIE_OAUTH_ACCESS_NONCE );
 		my_unset_cookie( COOKIE_WIKI_USERNAME );
 		my_unset_cookie( COOKIE_WIKI_CSRF );
 
 		// POST -> redirect -> GET
 		http_redirect( '' );
 	}
 
 	/**
 	 * Redirect to the OAuth login page
 	 */
 	private function tryOAuthLogin() {
 
 		// thanks for submitting the form!
 		list( $auth_url, $request_token ) = $this->client->initiate();
 
 		// remember the OAuth request token
 		my_set_cookie( COOKIE_OAUTH_REQUEST_TOKEN_KEY,    $request_token->key    );
 		my_set_cookie( COOKIE_OAUTH_REQUEST_TOKEN_SECRET, $request_token->secret );
 
 		// here we go!
 		http_redirect( $auth_url );
 
 	}
 
 
 	/**
 	 * Receive the OAuth response and redirect to the homepage again
 	 */
 	private function receiveOAuthResponse() {
 
 		// welcome back, user, what was the original OAuth request token?
 		$request_token_key = $_COOKIE[ COOKIE_OAUTH_REQUEST_TOKEN_KEY    ] ?? null;
 		$request_token_sec = $_COOKIE[ COOKIE_OAUTH_REQUEST_TOKEN_SECRET ] ?? null;
 		if( !$request_token_key || !$request_token_key ) {
 			throw new Exception( "missing request tokens" );
 		}
 
 		// rebuild the OAuth request token
 		$request_token = new Token( $request_token_key, $request_token_sec );
 
 		// check the OAuth access token
 		$access_token = $this->client->complete( $request_token, $_GET['oauth_verifier'] );
 		$identity     = $this->client->identify( $access_token );
 
 		// clear old cookies now unuseful
 		my_unset_cookie( COOKIE_OAUTH_REQUEST_TOKEN_KEY );
 		my_unset_cookie( COOKIE_OAUTH_REQUEST_TOKEN_SECRET );
 
 		// save the access token to rebuild it later
 		my_set_cookie( COOKIE_OAUTH_ACCESS_TOKEN_KEY,    $access_token->key );
 		my_set_cookie( COOKIE_OAUTH_ACCESS_TOKEN_SECRET, $access_token->secret );
 
 		// save other information
 		my_set_cookie( COOKIE_OAUTH_ACCESS_NONCE, $identity->nonce );
 		my_set_cookie( COOKIE_WIKI_USERNAME,      $identity->username );
 
 		// clean the URL
 		http_redirect( '' );
 
 	}
 
 	/**
 	 * Prepare the OAuth access token from cookies
 	 */
 	private function prepareOAuthAccessToken() {
 
 		// eventually build the OAuth access token
 		if( isset(
 			$_COOKIE[ COOKIE_OAUTH_ACCESS_TOKEN_KEY ],
 			$_COOKIE[ COOKIE_OAUTH_ACCESS_TOKEN_SECRET ]
 		) ) {
 			$this->accessToken = new Token(
 				$_COOKIE[ COOKIE_OAUTH_ACCESS_TOKEN_KEY ],
 				$_COOKIE[ COOKIE_OAUTH_ACCESS_TOKEN_SECRET ]
 			);
 		}
 
 	}
 
 	/**
 	 * Request the wiki's CSRF
 	 *
 	 * @return string
 	 */
 	private function requestWikiCSRFToken() {
 
 		// retrieve wiki CSRF token
 		$response_tokens =
 			$this->makeOAuthPOST( [
 				'action' => 'query',
 				'format' => 'json',
 				'meta'   => 'tokens',
 				'type'   => 'csrf',
 			] );
 
 		// no CSRF token no party
 		$csrf_token = $response_tokens->query->tokens->csrftoken ?? null;
 		if( !$csrf_token ) {
 			throw new Exception( "cannot retrieve CSRF token from wiki" );
 		}
 
 		return $csrf_token;
 
 	}
 
 	/**
 	 * Try to create the Event from the POST-ed data
 	 */
 	private function createEvent() {
 
 		// read POST-ed data
 		// assume that this data has sense (the user is logged-in and anyway he/she is just editing a page)
 		// in the worst of the cases, the event will be broken and a warning will be shown
 		$event_title      = $this->getPOST( 'event_title' );
 		$event_date_start = $this->getPOST( 'event_date_start' );
 		$event_date_end   = $this->getPOST( 'event_date_end' );
 		$event_time_start = $this->getPOST( 'event_time_start' );
 		$event_time_end   = $this->getPOST( 'event_time_end' );
 		$event_url        = $this->getPOST( 'event_url' );
+		$event_category   = $this->getPOST( 'event_category' );
 
 		// no dates no party
 		if( empty( $event_date_start ) ) {
 			throw new Exception( "missing date start" );
 		}
 
 		// get the wiki CSRF token
 		$csrf_token = $this->requestWikiCSRFToken();
 		if( !$csrf_token ) {
 			throw new Exception( "missing CSRF token from session" );
 		}
 
 		// this is the page that will host the event infobox
 		$this->eventsPageTitle = "Meta:Cronos/Events/$event_date_start";
 
 		// split date in parts
 		$event_date_start_parts = explode( '-', $event_date_start );
 		if( count( $event_date_start_parts ) !== 3 ) {
 			throw new Exception( "bad start date" );
 		}
 		list( $start_y, $start_m, $start_d ) = $event_date_start_parts;
 
 		// text of the page
 		$text_create = sprintf(
 			'{{Cronos day|%d|%d|%d}}',
 			$start_y,
 			$start_m,
 			$start_d
 		);
 
 		$template_event =
 			"\n" .
 			"{{Cronos event\n" .
-			"| title = $event_title\n" .
-			"| when  = $event_date_start $event_time_start\n" .
-			"| end   = $event_date_end $event_time_end\n" .
-			"| url   = $event_url\n" .
+			"|title    = $event_title\n" .
+			"|when     = $event_date_start $event_time_start\n" .
+			"|end      = $event_date_end $event_time_end\n" .
+			"|url      = $event_url\n" .
+			"|category = $event_category\n" .
 			"}}";
 
 		$text_create .= $template_event;
 
 		// try to create the page
 		$response = $this->makeOAuthPOST( [
 			'action'     => 'edit',
 			'createonly' => 1,
 			'format'     => 'json',
 			'title'      => $this->getEventsPageTitle(),
-			'summary'    => "New event: $event_title",
+			'summary'    => "New events page: $event_title",
 			'text'       => $text_create,
 			'token'      => $csrf_token,
 		] );
 
 		// eventually edit the page
 		$result = $response->edit->result ?? null;
 
 		$this->saved = $result === 'Success';
 
 		// check if the page already exist and append text
 		if( !$this->saved ) {
 
 			$error_code = $response->error->code ?? null;
 			if( $error_code === 'articleexists' ) {
 
 				// create the page
 				$response = $this->makeOAuthPOST( [
 					'action'     => 'edit',
 					'nocreate'   => 1,
 					'format'     => 'json',
 					'title'      => $this->getEventsPageTitle(),
 					'summary'    => "New event: $event_title",
 					'appendtext' => $template_event,
 					'token'      => $csrf_token,
 				] );
 
 				// assume success
 				$this->saved = true;
 			} else {
 
 				throw new Exception( $error_code );
 
 			}
 		}
 	}
 
 	/**
 	 * Make an OAuth HTTP POST request
 	 *
 	 * @param array $data
 	 * @return array
 	 */
 	private function makeOAuthPOST( $data ) {
 
 		// try to make the HTTP request
 		$response_raw = $this->client->makeOAuthCall( $this->accessToken, $this->wikiApi, $isPost = true, $data );
 		if( !$response_raw ) {
 			throw new Exception( "missing response" );
 		}
 
 		// try to parse JSON
 		$response = @json_decode( $response_raw );
 		if( !$response ) {
 			throw new Exception( "response not a JSON" );
 		}
 
 		return $response;
 
 	}
 }
diff --git a/load-post.php b/load-post.php
index 48e5c84..8c25185 100644
--- a/load-post.php
+++ b/load-post.php
@@ -1,33 +1,47 @@
 <?php
 # Copyright (C) 2020 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 // this file is called after the suckless-php/load.php file
 
 // require some dummy functions
 require ABSPATH . '/include/functions.php';
 
-// require some dummy functions
+// require some dummy classes
 require ABSPATH . '/include/class-CronosHomepage.php';
+require ABSPATH . '/include/class-Category.php';
 
 // MaterializeCSS
 // https://materializecss.com/
 register_js(  'materialize', 'static/materialize/js/materialize.min.js', 'footer' );
 register_css( 'materialize', 'static/materialize/css/materialize.min.css' );
 
 // register JavaScript files
 register_js( 'cronos', 'static/cronos.js', 'footer', [
 	'materialize',
 ] );
+
+// register some dummy categories in order of appearance
+Category::addInitiatives( 'com',    __( "Community" ),                     'Wikimedia Community Logo.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/7/75/Wikimedia_Community_Logo.svg/%dpx-Wikimedia_Community_Logo.svg.png' );
+Category::addInitiatives( 'dat',    __( "Wikidata" ),                      'Wikidata Favicon color.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Wikidata_Favicon_color.svg/%spx-Wikidata_Favicon_color.svg.png' );
+Category::add(            'edu',    __( "Wikimedia Education Program" ),   'WikipediaEduBelow.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/6/62/WikipediaEduBelow.svg/%dpx-WikipediaEduBelow.svg.png' );
+Category::addInitiatives( 'libre',  __( "Free Software and Open Source" ), 'Heckert GNU white.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Heckert_GNU_white.svg/%dpx-Heckert_GNU_white.svg.png' );
+Category::add(            'osm',      "OpenStreetMap",                     'Openstreetmap logo.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/b/b0/Openstreetmap_logo.svg/%dpx-Openstreetmap_logo.svg.png' );
+Category::add(            'glam',   __( "Wikimedia GLAM Program" ),        'GLAM logo.png', 'https://upload.wikimedia.org/wikipedia/commons/thumb/0/06/GLAM_logo.png/%dpx-GLAM_logo.png' );
+Category::addInitiatives( 'wmch',   __( "Wikimedia CH" ),                  'WikimediaCHLogo.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/WikimediaCHLogo.svg/%dpx-WikimediaCHLogo.svg.png' );
+Category::addInitiatives( 'wmf',    __( "Wikimedia Foundation" ),          'Wikimedia-logo black.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Wikimedia-logo_black.svg/%dpx-Wikimedia-logo_black.svg.png' );
+
+// this should be an alias of libre
+// Category::addInitiatives( 'osi',  __( "Open Source" ),                 'Opensource.svg', 'https://upload.wikimedia.org/wikipedia/commons/thumb/4/42/Opensource.svg/%dpx-Opensource.svg.png' );
diff --git a/template/form-login.php b/template/form-login.php
index 1951f0c..4db294e 100644
--- a/template/form-login.php
+++ b/template/form-login.php
@@ -1,33 +1,33 @@
 <?php
 # Copyright (C) 2020 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 ?>
 			<!-- start form login -->
 			<form method="post" class="card-panel">
 
 				<?php form_action( 'login' ) ?>
 
 				<div class="row">
 					<div class="col s12 m6 input-field">
 
 						<h2><?= __( "Create Event") ?></h2>
 
-						<p class="flow-text"><?= __( "Please login to create an Event.") ?></p>
+						<p class="flow-text"><?= __( "Please login to create a Cronos Event:" ) ?></p>
 						<button type="submit" class="btn-large waves-effect"><?= __( "Quick Login" ) ?></button>
 					</div>
 				</div>
 			</form>
 			<!-- end form login -->
diff --git a/www/credits.php b/www/credits.php
new file mode 100644
index 0000000..f868be9
--- /dev/null
+++ b/www/credits.php
@@ -0,0 +1,62 @@
+<?php
+# Copyright (C) 2020 Valerio Bozzolan
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// load the configuration file and autoload classes
+require 'load.php';
+
+// enqueue default stylesheet
+enqueue_js( 'cronos' );
+
+template( 'header' );
+?>
+	<div class="container">
+		<h1>Wikimedia CH Cronos &mdash; <?= __( "Credits" ) ?></h1>
+
+		<div class="card-panel">
+			<h2><?= __( "Image credits" ) ?></h2>
+			<p class="flow-text"><?= __( "Visit the related page to see the image author and the license." ) ?></p>
+			<ul class="collection">
+				<?php foreach( Category::all() as $category ): ?>
+					<li class="collection-item"><a href="<?= esc_attr( $category->getCommonsURL() ) ?>"><img src="<?= esc_attr( $category->getImageURL() ) ?>" /> <?= $category->getFilename() ?></a></li>
+				<?php endforeach ?>
+			</ul>
+		</div>
+
+		<div class="card-panel">
+			<h3><?= __( "Nerd stuff" ) ?></h3>
+			<p><?= __( "This block of information can be used inside your wiki to inherit these official categories. Ignore this part if you are not truly nerd to avoid brain explosion." ) ?></p>
+			<pre><?php
+				// print some Lua code
+				foreach( Category::all() as $category ) {
+					printf(
+						"['%1\$s'] = { uid: '%1\$s', name: '%2\$s', filename: 'File:%3\$s' },\n",
+						$category->getUID(),
+						$category->getName(),
+						$category->getFilename()
+					);
+				}
+
+			?></pre>
+		</div>
+
+		<div class="divider"></div>
+
+		<p><a href="<?= ROOT ?>/" class="btn waves-effect"><?= __( "Home" ) ?></a></p>
+	</div>
+
+<?php
+
+template( 'footer' );
diff --git a/www/index.php b/www/index.php
index e42c5be..9b596e4 100644
--- a/www/index.php
+++ b/www/index.php
@@ -1,173 +1,191 @@
 <?php
 # Copyright (C) 2020 Valerio Bozzolan
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation, either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU Affero General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 // load the configuration file and autoload classes
 require 'load.php';
 
 $page = new CronosHomepage();
 
 $page->printHeader();
 ?>
 	<div class="container">
 		<h1>Wikimedia CH Cronos</h1>
 
 		<?php /* check if the user has saved the page */ ?>
 		<?php if( $page->isEventsPageTitleKnown() ): ?>
 
 			<div class="card-panel green">
 
 				<?php if( $page->hasSaved() ): ?>
 					<h2><?= __( "Success!" ) ?></h2>
 				<?php endif ?>
 
 				<p class="flow-text"><?= __( "See/Edit your Event:" ) ?></p>
 
 				<p><?= HTML::a(
 					$page->getEventsPageURL(),
 					$page->getEventsPageTitle(),
-					__( "Show on wiki" ),
+					__( "Show on wiki" )
 				) ?></p>
 
 				<p><?= __( "Thank you!" ) ?>
 			</div>
 
 		<?php endif ?>
 		<?php /* end if the user has saved the page */ ?>
 
 
 		<?php /* check if the user IS NOT probably authenticated */ ?>
 		<?php if( $page->isUserUnknown() ): ?>
 
 			<?php template( 'form-login' ) ?>
 
 		<?php /* check if the user IS authenticated but has not saved */ ?>
 		<?php elseif( !$page->hasSaved() ): ?>
 
 			<?php
 			/**
 			 * Note: here we just trust the username in the cookie
 			 *
 			 * Possible stupid concerns:
 			 * 1. «hey look at my computer! it shows "Welcome administrator!" whoa I'm an hacker!!»
 			 *    Well, in this page there is nothing to be protected so you can also be "my mother".
 			 *    Moreover, when you will save, the other wiki will throw:
 			 *       «f**k you, you are not "administrator", you cannot do this edit»
 			 *    So even if you play with your cookies you have hacked nothing.
 			 /    Anyway this field is XSS safe.
 			 */
 			?>
 			<div class="card-panel">
 				<p class="flow-text"><?= sprintf(
 					__( "Welcome %s!" ),
 					esc_html( $page->getAnnouncedUsername() )
 				) ?></p>
 			</div>
 
 			<!-- start form create event -->
 			<form method="post" class="card-panel">
 
 				<h2><?= __( "Create Event" ) ?></h2>
 
 				<?php form_action( 'create-event' ) ?>
 
 				<div class="row">
 					<div class="col s12 m6 input-field">
 
 						<input type="text" name="event_title" id="event-title" class="validate"<?= value( $page->getPOST( 'event_title' ) ) ?> />
 						<label for="event-title"><?= __( "Event Title" ) ?> *</label>
 
 					</div>
 				</div>
 
 				<div class="row">
 
 					<div class="col s12 m6 input-field">
 
 						<input type="text" name="event_date_start" id="event-date-start" class="datepicker" required="required" />
-						<label for="event-date-start"><?= __( "Start Date" ) ?></label>
+						<label for="event-date-start"><?= __( "Start Date" ) ?> *</label>
 
 					</div>
 
 					<div class="col s12 m6 input-field">
 
 						<input type="text" name="event_time_start" id="event-time-start" class="timepicker" required="required" />
-						<label for="event-time-start"><?= __( "Start Time" ) ?></label>
+						<label for="event-time-start"><?= __( "Start Time" ) ?> *</label>
 
 					</div>
 
 				</div>
 
 				<div class="row">
 
 					<div class="col s12 m6 input-field">
 
 						<input type="text" name="event_date_end" id="event-date-end" class="datepicker" />
 						<label for="event-date-end"><?= __( "End Date" ) ?></label>
 
 					</div>
 
 
 					<div class="col s12 m6 input-field">
 
 						<input type="text" name="event_time_end" id="event-time-end" class="timepicker" required="required" />
-						<label for="event-time-end"><?= __( "End Time" ) ?></label>
+						<label for="event-time-end"><?= __( "End Time" ) ?> *</label>
+
+					</div>
+
+				</div>
+
+				<div class="row">
+
+					<div class="col s12 input-field">
+
+						<select name="event_category" id="event-category" class="icons" required="required">
+							<option value="" disabled selected><?= __( "Choose your option" ) ?></option>
+							<?php foreach( Category::all() as $category ): ?>
+								<option value="<?= $category->getUID() ?>" data-icon="<?= $category->getImageURL() ?>" class="left"><?= $category->getName() ?></option>
+							<?php endforeach ?>
+						</select>
+						<label for="event-category"><?= __( "Category" ) ?> *</label>
 
 					</div>
 
 				</div>
 
 				<div class="row">
 
 					<div class="col s12 input-field">
 
 						<input type="text" placeholder="https://" name="event_url" id="event-url" />
 						<label for="event-url"><?= __( "External URL" ) ?></label>
 
 					</div>
 
 				</div>
 
 				<div class="row">
 
-					<div class="col s12 m6 input-field">
+					<div class="col s12 input-field">
 
-						<button type="submit" class="btn waves-effect"><?= __( "Save Event" ) ?></button>
 
 						<p><?= __( "Note: your edit will be published under the terms of Meta-wiki. Do not press if unsure." ) ?></p>
 
+						<p><button type="submit" class="btn-large waves-effect">
+							<?= __( "Save Event" ) ?></button>
+						</p>
 					</div>
 
 				</div>
 
 			</form>
 			<!-- end form create event -->
 
 		<?php /* end if the user IS probably authenticated - end */ ?>
 		<?php endif ?>
 
 	</div>
 
 	<!-- start logout form -->
 	<?php if( isset( $known_user ) ): ?>
 
 		<?php template( 'form-logout' ) ?>
 
 	<?php endif ?>
 	<!-- end logout form -->
 
 <?php
 
 $page->printFooter();
diff --git a/www/static/cronos.js b/www/static/cronos.js
index d53dd26..5a10885 100644
--- a/www/static/cronos.js
+++ b/www/static/cronos.js
@@ -1,34 +1,40 @@
 ( function() {
 
 	document.addEventListener( 'DOMContentLoaded', function() {
 
 		// initialize date pickers
 		( function() {
 			var elems = document.querySelectorAll( '.datepicker' );
 			var instances = M.Datepicker.init( elems, {
 				format: 'yyyy-mm-dd',
 				firstDay: 1,
 				onSelect: function( date ) {
 
 				}
 			} );
 
 			// avoid to select an end date before the start date
 			var start = M.Datepicker.getInstance( document.getElementById( 'event-date-start' ) );
 			var stop  = M.Datepicker.getInstance( document.getElementById( 'event-date-end'   ) );
 			start.options.onSelect = function( date ) {
 				stop.options.minDate = date;
 			};
 		} )();
 
 		// initialize time pickers
 		( function() {
 			var elems = document.querySelectorAll( '.timepicker' );
 			var instances = M.Timepicker.init( elems, {
 				twelveHour: false,
 			} );
 		} )();
+
+		// initialize the select boxes
+		( function() {
+			var elems = document.querySelectorAll( 'select' );
+			var instances = M.FormSelect.init( elems );
+		} )();
 	} );
 
 } )();