Issue #827468 by paulmartin84, latikas, aburrows, alimac, fatfish,...

Issue #827468 by paulmartin84, latikas, aburrows, alimac, fatfish, rocket_nova, Truptti, pektinasen, DuaelFr, YesCT, ifrik, John Cook, danylevskyi, dcam, anil.gangwal, gajendra sharma, danharper, mgriego, realityloop, bleen18, alvar0hurtad0, dddave, droplet, susanb, nlisgo, webchick, meeli: Fix the allowed punctuation wording in user_edit_form

core/lib/Drupal/Core/Installer/Form/SiteConfigureForm.php

@@ -174,7 +174,7 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#type' => 'textfield',
       '#title' => $this->t('Username'),
       '#maxlength' => USERNAME_MAX_LENGTH,
-      '#description' => $this->t('Spaces are allowed; punctuation is not allowed except for periods, hyphens, and underscores.'),
+      '#description' => $this->t("Several special characters are allowed, including space, period (.), hyphen (-), apostrophe ('), underscore (_), and the @ sign."),
       '#required' => TRUE,
       '#attributes' => array('class' => array('username')),
     );

core/modules/user/src/AccountForm.php

@@ -104,7 +104,7 @@ public function form(array $form, FormStateInterface $form_state) {
       '#type' => 'textfield',
       '#title' => $this->t('Username'),
       '#maxlength' => USERNAME_MAX_LENGTH,
-      '#description' => $this->t('Spaces are allowed; punctuation is not allowed except for periods, hyphens, apostrophes, and underscores.'),
+      '#description' => $this->t("Several special characters are allowed, including space, period (.), hyphen (-), apostrophe ('), underscore (_), and the @ sign."),
       '#required' => TRUE,
       '#attributes' => array(
         'class' => array('username'),