diff --git a/fn/auth.php b/fn/auth.php
index 06e47dd..c3c8843 100644
--- a/fn/auth.php
+++ b/fn/auth.php
@@ -1,18 +1,18 @@
 <?php
 
-define("USERNAME_REGEX", "^[\p{L}\p{N}_-]{1,64}$");
-define("PASSWORD_REGEX", "^(?=.*[\p{Ll}])(?=.*[\p{Lu}])(?=.*[\p{N}]).{8,1024}|.{10,1024}$");
+const USERNAME_REGEX = '^[\p{L}\p{N}_-]{1,64}$';
+const PASSWORD_REGEX = '^(?=.*[\p{Ll}])(?=.*[\p{Lu}])(?=.*[\p{N}]).{8,1024}|.{10,1024}$';
 
-define("PLACEHOLDER_USERNAME", "lain");
-define("PLACEHOLDER_PASSWORD", "••••••••••••••••••••••••");
+const PLACEHOLDER_USERNAME = 'lain';
+const PLACEHOLDER_PASSWORD = '••••••••••••••••••••••••';
 
 // Password storage security
-define("ALGO_PASSWORD", PASSWORD_ARGON2ID);
-define("OPTIONS_PASSWORD", array(
+const ALGO_PASSWORD = PASSWORD_ARGON2ID;
+const OPTIONS_PASSWORD = [
 	"memory_cost" => 65536,
 	"time_cost" => 24,
 	"threads" => 64,
-));
+];
 
 function checkPasswordFormat($password) {
 	if (preg_match("/" . PASSWORD_REGEX . "/u", $password) !== 1)
diff --git a/pages/auth/login.php b/pages/auth/login.php
index fd23469..5fbf302 100644
--- a/pages/auth/login.php
+++ b/pages/auth/login.php
@@ -25,7 +25,7 @@ if (processForm(false)) {
 
 <form method="post">
 	<label for="username">Identifiant</label><br>
-	<input required="" minlength="4" maxlength="32" pattern="<?= USERNAME_REGEX ?>" id="username" name="username" type="text" placeholder="<?= PLACEHOLDER_USERNAME ?>">
+	<input required="" minlength="1" maxlength="64" pattern="<?= USERNAME_REGEX ?>" id="username" name="username" type="text" placeholder="<?= PLACEHOLDER_USERNAME ?>">
 	<br>
 
 	<label for="password">Clé de passe</label><br>
diff --git a/pages/auth/register.php b/pages/auth/register.php
index a63d671..dbfb94c 100644
--- a/pages/auth/register.php
+++ b/pages/auth/register.php
@@ -50,7 +50,7 @@ if (processForm(false)) {
 		<summary><label for="username">Identifiant</label></summary>
 		Uniquement composé de lettres minuscules.
 	</details>
-	<input id="username" maxlength="32" pattern="<?= USERNAME_REGEX ?>" required="" name="username" type="text" placeholder="<?= PLACEHOLDER_USERNAME ?>"><br>
+	<input id="username" minlength="1" maxlength="64" pattern="<?= USERNAME_REGEX ?>" required="" name="username" type="text" placeholder="<?= PLACEHOLDER_USERNAME ?>"><br>
 
 	<details>
 		<summary><label for="password">Clé de passe</label></summary>
diff --git a/pages/reg/register.php b/pages/reg/register.php
index 97cd77b..53dccf9 100644
--- a/pages/reg/register.php
+++ b/pages/reg/register.php
@@ -1,8 +1,8 @@
 <?php
 
 if (processForm()) {
-	if (preg_match("/" . CONF['reg']['subdomain_regex'] . "/", $_POST['subdomain']) !== 1)
-	output(403, 'Erreur : Le nom de domaine doit être composé uniquement d\'entre 4 et 63 lettres minuscules (a-z)');
+	if (preg_match('/' . CONF['reg']['subdomain_regex'] . '/', $_POST['subdomain']) !== 1)
+		output(403, 'Le nom de domaine doit être composé uniquement d\'entre 4 et 63 lettres minuscules ou chiffre (a-z et 0-9)');
 
 	$domain = formatAbsoluteDomain($_POST['subdomain'] . '.' . CONF['reg']['registry']);