diff --git a/src/wp-admin/includes/file.php b/src/wp-admin/includes/file.php
index 399fdcf629..29db73767d 100644
--- a/src/wp-admin/includes/file.php
+++ b/src/wp-admin/includes/file.php
@@ -2326,7 +2326,7 @@ function request_filesystem_credentials( $form_post, $type = '', $error = false,
 	$connection_type = isset( $credentials['connection_type'] ) ? $credentials['connection_type'] : '';
 
 	if ( $error ) {
-		$error_string = __( '<strong>Error</strong>: Could not connect to the server. Please verify the settings are correct.' );
+		$error_string = __( '<strong>Error:</strong> Could not connect to the server. Please verify the settings are correct.' );
 		if ( is_wp_error( $error ) ) {
 			$error_string = esc_html( $error->get_error_message() );
 		}
diff --git a/src/wp-admin/includes/user.php b/src/wp-admin/includes/user.php
index ab63f9e302..b6dc7919ae 100644
--- a/src/wp-admin/includes/user.php
+++ b/src/wp-admin/includes/user.php
@@ -143,12 +143,12 @@ function edit_user( $user_id = 0 ) {
 
 	/* checking that username has been typed */
 	if ( '' === $user->user_login ) {
-		$errors->add( 'user_login', __( '<strong>Error</strong>: Please enter a username.' ) );
+		$errors->add( 'user_login', __( '<strong>Error:</strong> Please enter a username.' ) );
 	}
 
 	/* checking that nickname has been typed */
 	if ( $update && empty( $user->nickname ) ) {
-		$errors->add( 'nickname', __( '<strong>Error</strong>: Please enter a nickname.' ) );
+		$errors->add( 'nickname', __( '<strong>Error:</strong> Please enter a nickname.' ) );
 	}
 
 	/**
@@ -164,17 +164,17 @@ function edit_user( $user_id = 0 ) {
 
 	// Check for blank password when adding a user.
 	if ( ! $update && empty( $pass1 ) ) {
-		$errors->add( 'pass', __( '<strong>Error</strong>: Please enter a password.' ), array( 'form-field' => 'pass1' ) );
+		$errors->add( 'pass', __( '<strong>Error:</strong> Please enter a password.' ), array( 'form-field' => 'pass1' ) );
 	}
 
 	// Check for "\" in password.
 	if ( false !== strpos( wp_unslash( $pass1 ), '\\' ) ) {
-		$errors->add( 'pass', __( '<strong>Error</strong>: Passwords may not contain the character "\\".' ), array( 'form-field' => 'pass1' ) );
+		$errors->add( 'pass', __( '<strong>Error:</strong> Passwords may not contain the character "\\".' ), array( 'form-field' => 'pass1' ) );
 	}
 
 	// Checking the password has been typed twice the same.
 	if ( ( $update || ! empty( $pass1 ) ) && $pass1 != $pass2 ) {
-		$errors->add( 'pass', __( '<strong>Error</strong>: Passwords don&#8217;t match. Please enter the same password in both password fields.' ), array( 'form-field' => 'pass1' ) );
+		$errors->add( 'pass', __( '<strong>Error:</strong> Passwords don&#8217;t match. Please enter the same password in both password fields.' ), array( 'form-field' => 'pass1' ) );
 	}
 
 	if ( ! empty( $pass1 ) ) {
@@ -182,29 +182,29 @@ function edit_user( $user_id = 0 ) {
 	}
 
 	if ( ! $update && isset( $_POST['user_login'] ) && ! validate_username( $_POST['user_login'] ) ) {
-		$errors->add( 'user_login', __( '<strong>Error</strong>: This username is invalid because it uses illegal characters. Please enter a valid username.' ) );
+		$errors->add( 'user_login', __( '<strong>Error:</strong> This username is invalid because it uses illegal characters. Please enter a valid username.' ) );
 	}
 
 	if ( ! $update && username_exists( $user->user_login ) ) {
-		$errors->add( 'user_login', __( '<strong>Error</strong>: This username is already registered. Please choose another one.' ) );
+		$errors->add( 'user_login', __( '<strong>Error:</strong> This username is already registered. Please choose another one.' ) );
 	}
 
 	/** This filter is documented in wp-includes/user.php */
 	$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );
 
 	if ( in_array( strtolower( $user->user_login ), array_map( 'strtolower', $illegal_logins ), true ) ) {
-		$errors->add( 'invalid_username', __( '<strong>Error</strong>: Sorry, that username is not allowed.' ) );
+		$errors->add( 'invalid_username', __( '<strong>Error:</strong> Sorry, that username is not allowed.' ) );
 	}
 
 	/* checking email address */
 	if ( empty( $user->user_email ) ) {
-		$errors->add( 'empty_email', __( '<strong>Error</strong>: Please enter an email address.' ), array( 'form-field' => 'email' ) );
+		$errors->add( 'empty_email', __( '<strong>Error:</strong> Please enter an email address.' ), array( 'form-field' => 'email' ) );
 	} elseif ( ! is_email( $user->user_email ) ) {
-		$errors->add( 'invalid_email', __( '<strong>Error</strong>: The email address isn&#8217;t correct.' ), array( 'form-field' => 'email' ) );
+		$errors->add( 'invalid_email', __( '<strong>Error:</strong> The email address isn&#8217;t correct.' ), array( 'form-field' => 'email' ) );
 	} else {
 		$owner_id = email_exists( $user->user_email );
 		if ( $owner_id && ( ! $update || ( $owner_id != $user->ID ) ) ) {
-			$errors->add( 'email_exists', __( '<strong>Error</strong>: This email is already registered. Please choose another one.' ), array( 'form-field' => 'email' ) );
+			$errors->add( 'email_exists', __( '<strong>Error:</strong> This email is already registered. Please choose another one.' ), array( 'form-field' => 'email' ) );
 		}
 	}
 
diff --git a/src/wp-admin/options.php b/src/wp-admin/options.php
index 019f9529c4..1ee1be57e5 100644
--- a/src/wp-admin/options.php
+++ b/src/wp-admin/options.php
@@ -238,7 +238,7 @@ if ( 'update' === $action ) { // We are saving settings sent from a settings pag
 		wp_die(
 			sprintf(
 				/* translators: %s: The options page name. */
-				__( '<strong>Error</strong>: Options page %s not found in the allowed options list.' ),
+				__( '<strong>Error:</strong> Options page %s not found in the allowed options list.' ),
 				'<code>' . esc_html( $option_page ) . '</code>'
 			)
 		);
diff --git a/src/wp-admin/setup-config.php b/src/wp-admin/setup-config.php
index 881398ff57..2b61fe643c 100644
--- a/src/wp-admin/setup-config.php
+++ b/src/wp-admin/setup-config.php
@@ -277,12 +277,12 @@ switch ( $step ) {
 		$tryagain_link = '</p><p class="step"><a href="' . $step_1 . '" onclick="javascript:history.go(-1);return false;" class="button button-large">' . __( 'Try Again' ) . '</a>';
 
 		if ( empty( $prefix ) ) {
-			wp_die( __( '<strong>Error</strong>: "Table Prefix" must not be empty.' ) . $tryagain_link );
+			wp_die( __( '<strong>Error:</strong> "Table Prefix" must not be empty.' ) . $tryagain_link );
 		}
 
 		// Validate $prefix: it can only contain letters, numbers and underscores.
 		if ( preg_match( '|[^a-z0-9_]|i', $prefix ) ) {
-			wp_die( __( '<strong>Error</strong>: "Table Prefix" can only contain numbers, letters, and underscores.' ) . $tryagain_link );
+			wp_die( __( '<strong>Error:</strong> "Table Prefix" can only contain numbers, letters, and underscores.' ) . $tryagain_link );
 		}
 
 		// Test the DB connection.
@@ -315,7 +315,7 @@ switch ( $step ) {
 		$wpdb->show_errors( $errors );
 		if ( ! $wpdb->last_error ) {
 			// MySQL was able to parse the prefix as a value, which we don't want. Bail.
-			wp_die( __( '<strong>Error</strong>: "Table Prefix" is invalid.' ) );
+			wp_die( __( '<strong>Error:</strong> "Table Prefix" is invalid.' ) );
 		}
 
 		// Generate keys and salts using secure CSPRNG; fallback to API if enabled; further fallback to original wp_generate_password().
diff --git a/src/wp-includes/comment.php b/src/wp-includes/comment.php
index c2892f16b1..35895404de 100644
--- a/src/wp-includes/comment.php
+++ b/src/wp-includes/comment.php
@@ -1296,19 +1296,19 @@ function wp_check_comment_data_max_lengths( $comment_data ) {
 	$max_lengths = wp_get_comment_fields_max_lengths();
 
 	if ( isset( $comment_data['comment_author'] ) && mb_strlen( $comment_data['comment_author'], '8bit' ) > $max_lengths['comment_author'] ) {
-		return new WP_Error( 'comment_author_column_length', __( '<strong>Error</strong>: Your name is too long.' ), 200 );
+		return new WP_Error( 'comment_author_column_length', __( '<strong>Error:</strong> Your name is too long.' ), 200 );
 	}
 
 	if ( isset( $comment_data['comment_author_email'] ) && strlen( $comment_data['comment_author_email'] ) > $max_lengths['comment_author_email'] ) {
-		return new WP_Error( 'comment_author_email_column_length', __( '<strong>Error</strong>: Your email address is too long.' ), 200 );
+		return new WP_Error( 'comment_author_email_column_length', __( '<strong>Error:</strong> Your email address is too long.' ), 200 );
 	}
 
 	if ( isset( $comment_data['comment_author_url'] ) && strlen( $comment_data['comment_author_url'] ) > $max_lengths['comment_author_url'] ) {
-		return new WP_Error( 'comment_author_url_column_length', __( '<strong>Error</strong>: Your URL is too long.' ), 200 );
+		return new WP_Error( 'comment_author_url_column_length', __( '<strong>Error:</strong> Your URL is too long.' ), 200 );
 	}
 
 	if ( isset( $comment_data['comment_content'] ) && mb_strlen( $comment_data['comment_content'], '8bit' ) > $max_lengths['comment_content'] ) {
-		return new WP_Error( 'comment_content_column_length', __( '<strong>Error</strong>: Your comment is too long.' ), 200 );
+		return new WP_Error( 'comment_content_column_length', __( '<strong>Error:</strong> Your comment is too long.' ), 200 );
 	}
 
 	return true;
@@ -3549,9 +3549,9 @@ function wp_handle_comment_submission( $comment_data ) {
 
 	if ( get_option( 'require_name_email' ) && ! $user->exists() ) {
 		if ( '' == $comment_author_email || '' == $comment_author ) {
-			return new WP_Error( 'require_name_email', __( '<strong>Error</strong>: Please fill the required fields.' ), 200 );
+			return new WP_Error( 'require_name_email', __( '<strong>Error:</strong> Please fill the required fields.' ), 200 );
 		} elseif ( ! is_email( $comment_author_email ) ) {
-			return new WP_Error( 'require_valid_email', __( '<strong>Error</strong>: Please enter a valid email address.' ), 200 );
+			return new WP_Error( 'require_valid_email', __( '<strong>Error:</strong> Please enter a valid email address.' ), 200 );
 		}
 	}
 
@@ -3576,7 +3576,7 @@ function wp_handle_comment_submission( $comment_data ) {
 	 */
 	$allow_empty_comment = apply_filters( 'allow_empty_comment', false, $commentdata );
 	if ( '' === $comment_content && ! $allow_empty_comment ) {
-		return new WP_Error( 'require_valid_comment', __( '<strong>Error</strong>: Please type your comment text.' ), 200 );
+		return new WP_Error( 'require_valid_comment', __( '<strong>Error:</strong> Please type your comment text.' ), 200 );
 	}
 
 	$check_max_lengths = wp_check_comment_data_max_lengths( $commentdata );
@@ -3590,7 +3590,7 @@ function wp_handle_comment_submission( $comment_data ) {
 	}
 
 	if ( ! $comment_id ) {
-		return new WP_Error( 'comment_save_error', __( '<strong>Error</strong>: The comment could not be saved. Please try again later.' ), 500 );
+		return new WP_Error( 'comment_save_error', __( '<strong>Error:</strong> The comment could not be saved. Please try again later.' ), 500 );
 	}
 
 	return get_comment( $comment_id );
diff --git a/src/wp-includes/load.php b/src/wp-includes/load.php
index ffbc1d2290..69e017fc92 100644
--- a/src/wp-includes/load.php
+++ b/src/wp-includes/load.php
@@ -624,7 +624,7 @@ function wp_set_wpdb_vars() {
 		wp_die(
 			sprintf(
 				/* translators: 1: $table_prefix, 2: wp-config.php */
-				__( '<strong>Error</strong>: %1$s in %2$s can only contain numbers, letters, and underscores.' ),
+				__( '<strong>Error:</strong> %1$s in %2$s can only contain numbers, letters, and underscores.' ),
 				'<code>$table_prefix</code>',
 				'<code>wp-config.php</code>'
 			)
diff --git a/src/wp-includes/ms-deprecated.php b/src/wp-includes/ms-deprecated.php
index 1897e0f77b..5933d3fea0 100644
--- a/src/wp-includes/ms-deprecated.php
+++ b/src/wp-includes/ms-deprecated.php
@@ -401,7 +401,7 @@ function create_empty_blog( $domain, $path, $weblog_title, $site_id = 1 ) {
 
 	// Check if the domain has been used already. We should return an error message.
 	if ( domain_exists($domain, $path, $site_id) )
-		return __( '<strong>Error</strong>: Site URL you&#8217;ve entered is already taken.' );
+		return __( '<strong>Error:</strong> Site URL you&#8217;ve entered is already taken.' );
 
 	/*
 	 * Need to back up wpdb table names, and create a new wp_blogs entry for new blog.
@@ -410,7 +410,7 @@ function create_empty_blog( $domain, $path, $weblog_title, $site_id = 1 ) {
 	 */
 
 	if ( ! $blog_id = insert_blog($domain, $path, $site_id) )
-		return __( '<strong>Error</strong>: There was a problem creating site entry.' );
+		return __( '<strong>Error:</strong> There was a problem creating site entry.' );
 
 	switch_to_blog($blog_id);
 	install_blog($blog_id);
diff --git a/src/wp-includes/pluggable.php b/src/wp-includes/pluggable.php
index 4a5891b8fd..d79e9520c9 100644
--- a/src/wp-includes/pluggable.php
+++ b/src/wp-includes/pluggable.php
@@ -595,7 +595,7 @@ if ( ! function_exists( 'wp_authenticate' ) ) :
 		if ( null == $user ) {
 			// TODO: What should the error message be? (Or would these even happen?)
 			// Only needed if all authentication handlers fail to return anything.
-			$user = new WP_Error( 'authentication_failed', __( '<strong>Error</strong>: Invalid username, email address or incorrect password.' ) );
+			$user = new WP_Error( 'authentication_failed', __( '<strong>Error:</strong> Invalid username, email address or incorrect password.' ) );
 		}
 
 		$ignore_codes = array( 'empty_username', 'empty_password' );
diff --git a/src/wp-includes/user.php b/src/wp-includes/user.php
index 018c960c03..3c2431e6b4 100644
--- a/src/wp-includes/user.php
+++ b/src/wp-includes/user.php
@@ -134,11 +134,11 @@ function wp_authenticate_username_password( $user, $username, $password ) {
 		$error = new WP_Error();
 
 		if ( empty( $username ) ) {
-			$error->add( 'empty_username', __( '<strong>Error</strong>: The username field is empty.' ) );
+			$error->add( 'empty_username', __( '<strong>Error:</strong> The username field is empty.' ) );
 		}
 
 		if ( empty( $password ) ) {
-			$error->add( 'empty_password', __( '<strong>Error</strong>: The password field is empty.' ) );
+			$error->add( 'empty_password', __( '<strong>Error:</strong> The password field is empty.' ) );
 		}
 
 		return $error;
@@ -151,7 +151,7 @@ function wp_authenticate_username_password( $user, $username, $password ) {
 			'invalid_username',
 			sprintf(
 				/* translators: %s: User name. */
-				__( '<strong>Error</strong>: The username <strong>%s</strong> is not registered on this site. If you are unsure of your username, try your email address instead.' ),
+				__( '<strong>Error:</strong> The username <strong>%s</strong> is not registered on this site. If you are unsure of your username, try your email address instead.' ),
 				$username
 			)
 		);
@@ -176,7 +176,7 @@ function wp_authenticate_username_password( $user, $username, $password ) {
 			'incorrect_password',
 			sprintf(
 				/* translators: %s: User name. */
-				__( '<strong>Error</strong>: The password you entered for the username %s is incorrect.' ),
+				__( '<strong>Error:</strong> The password you entered for the username %s is incorrect.' ),
 				'<strong>' . $username . '</strong>'
 			) .
 			' <a href="' . wp_lostpassword_url() . '">' .
@@ -213,11 +213,11 @@ function wp_authenticate_email_password( $user, $email, $password ) {
 
 		if ( empty( $email ) ) {
 			// Uses 'empty_username' for back-compat with wp_signon().
-			$error->add( 'empty_username', __( '<strong>Error</strong>: The email field is empty.' ) );
+			$error->add( 'empty_username', __( '<strong>Error:</strong> The email field is empty.' ) );
 		}
 
 		if ( empty( $password ) ) {
-			$error->add( 'empty_password', __( '<strong>Error</strong>: The password field is empty.' ) );
+			$error->add( 'empty_password', __( '<strong>Error:</strong> The password field is empty.' ) );
 		}
 
 		return $error;
@@ -248,7 +248,7 @@ function wp_authenticate_email_password( $user, $email, $password ) {
 			'incorrect_password',
 			sprintf(
 				/* translators: %s: Email address. */
-				__( '<strong>Error</strong>: The password you entered for the email address %s is incorrect.' ),
+				__( '<strong>Error:</strong> The password you entered for the email address %s is incorrect.' ),
 				'<strong>' . $email . '</strong>'
 			) .
 			' <a href="' . wp_lostpassword_url() . '">' .
@@ -351,12 +351,12 @@ function wp_authenticate_application_password( $input_user, $username, $password
 		if ( is_email( $username ) ) {
 			$error = new WP_Error(
 				'invalid_email',
-				__( '<strong>Error</strong>: Unknown email address. Check again or try your username.' )
+				__( '<strong>Error:</strong> Unknown email address. Check again or try your username.' )
 			);
 		} else {
 			$error = new WP_Error(
 				'invalid_username',
-				__( '<strong>Error</strong>: Unknown username. Check again or try your email address.' )
+				__( '<strong>Error:</strong> Unknown username. Check again or try your email address.' )
 			);
 		}
 	} elseif ( ! wp_is_application_passwords_available() ) {
@@ -503,7 +503,7 @@ function wp_authenticate_spam_check( $user ) {
 		$spammed = apply_filters( 'check_is_user_spammed', is_user_spammy( $user ), $user );
 
 		if ( $spammed ) {
-			return new WP_Error( 'spammer_account', __( '<strong>Error</strong>: Your account has been marked as a spammer.' ) );
+			return new WP_Error( 'spammer_account', __( '<strong>Error:</strong> Your account has been marked as a spammer.' ) );
 		}
 	}
 	return $user;
@@ -2561,7 +2561,7 @@ function get_password_reset_key( $user ) {
 	global $wp_hasher;
 
 	if ( ! ( $user instanceof WP_User ) ) {
-		return new WP_Error( 'invalidcombo', __( '<strong>Error</strong>: There is no account with that username or email address.' ) );
+		return new WP_Error( 'invalidcombo', __( '<strong>Error:</strong> There is no account with that username or email address.' ) );
 	}
 
 	/**
@@ -2756,11 +2756,11 @@ function retrieve_password( $user_login = null ) {
 	}
 
 	if ( empty( $user_login ) ) {
-		$errors->add( 'empty_username', __( '<strong>Error</strong>: Please enter a username or email address.' ) );
+		$errors->add( 'empty_username', __( '<strong>Error:</strong> Please enter a username or email address.' ) );
 	} elseif ( strpos( $user_login, '@' ) ) {
 		$user_data = get_user_by( 'email', trim( wp_unslash( $user_login ) ) );
 		if ( empty( $user_data ) ) {
-			$errors->add( 'invalid_email', __( '<strong>Error</strong>: There is no account with that username or email address.' ) );
+			$errors->add( 'invalid_email', __( '<strong>Error:</strong> There is no account with that username or email address.' ) );
 		}
 	} else {
 		$user_data = get_user_by( 'login', trim( wp_unslash( $user_login ) ) );
@@ -2814,7 +2814,7 @@ function retrieve_password( $user_login = null ) {
 	}
 
 	if ( ! $user_data ) {
-		$errors->add( 'invalidcombo', __( '<strong>Error</strong>: There is no account with that username or email address.' ) );
+		$errors->add( 'invalidcombo', __( '<strong>Error:</strong> There is no account with that username or email address.' ) );
 		return $errors;
 	}
 
@@ -2901,7 +2901,7 @@ function retrieve_password( $user_login = null ) {
 			'retrieve_password_email_failure',
 			sprintf(
 				/* translators: %s: Documentation URL. */
-				__( '<strong>Error</strong>: The email could not be sent. Your site may not be correctly configured to send emails. <a href="%s">Get support for resetting your password</a>.' ),
+				__( '<strong>Error:</strong> The email could not be sent. Your site may not be correctly configured to send emails. <a href="%s">Get support for resetting your password</a>.' ),
 				esc_url( __( 'https://wordpress.org/support/article/resetting-your-password/' ) )
 			)
 		);
@@ -2968,29 +2968,29 @@ function register_new_user( $user_login, $user_email ) {
 
 	// Check the username.
 	if ( '' === $sanitized_user_login ) {
-		$errors->add( 'empty_username', __( '<strong>Error</strong>: Please enter a username.' ) );
+		$errors->add( 'empty_username', __( '<strong>Error:</strong> Please enter a username.' ) );
 	} elseif ( ! validate_username( $user_login ) ) {
-		$errors->add( 'invalid_username', __( '<strong>Error</strong>: This username is invalid because it uses illegal characters. Please enter a valid username.' ) );
+		$errors->add( 'invalid_username', __( '<strong>Error:</strong> This username is invalid because it uses illegal characters. Please enter a valid username.' ) );
 		$sanitized_user_login = '';
 	} elseif ( username_exists( $sanitized_user_login ) ) {
-		$errors->add( 'username_exists', __( '<strong>Error</strong>: This username is already registered. Please choose another one.' ) );
+		$errors->add( 'username_exists', __( '<strong>Error:</strong> This username is already registered. Please choose another one.' ) );
 
 	} else {
 		/** This filter is documented in wp-includes/user.php */
 		$illegal_user_logins = (array) apply_filters( 'illegal_user_logins', array() );
 		if ( in_array( strtolower( $sanitized_user_login ), array_map( 'strtolower', $illegal_user_logins ), true ) ) {
-			$errors->add( 'invalid_username', __( '<strong>Error</strong>: Sorry, that username is not allowed.' ) );
+			$errors->add( 'invalid_username', __( '<strong>Error:</strong> Sorry, that username is not allowed.' ) );
 		}
 	}
 
 	// Check the email address.
 	if ( '' === $user_email ) {
-		$errors->add( 'empty_email', __( '<strong>Error</strong>: Please type your email address.' ) );
+		$errors->add( 'empty_email', __( '<strong>Error:</strong> Please type your email address.' ) );
 	} elseif ( ! is_email( $user_email ) ) {
-		$errors->add( 'invalid_email', __( '<strong>Error</strong>: The email address isn&#8217;t correct.' ) );
+		$errors->add( 'invalid_email', __( '<strong>Error:</strong> The email address isn&#8217;t correct.' ) );
 		$user_email = '';
 	} elseif ( email_exists( $user_email ) ) {
-		$errors->add( 'email_exists', __( '<strong>Error</strong>: This email is already registered. Please choose another one.' ) );
+		$errors->add( 'email_exists', __( '<strong>Error:</strong> This email is already registered. Please choose another one.' ) );
 	}
 
 	/**
@@ -3035,7 +3035,7 @@ function register_new_user( $user_login, $user_email ) {
 			'registerfail',
 			sprintf(
 				/* translators: %s: Admin email address. */
-				__( '<strong>Error</strong>: Couldn&#8217;t register you&hellip; please contact the <a href="mailto:%s">site admin</a>!' ),
+				__( '<strong>Error:</strong> Couldn&#8217;t register you&hellip; please contact the <a href="mailto:%s">site admin</a>!' ),
 				get_option( 'admin_email' )
 			)
 		);
@@ -3271,7 +3271,7 @@ function send_confirmation_on_profile_email() {
 		if ( ! is_email( $_POST['email'] ) ) {
 			$errors->add(
 				'user_email',
-				__( '<strong>Error</strong>: The email address isn&#8217;t correct.' ),
+				__( '<strong>Error:</strong> The email address isn&#8217;t correct.' ),
 				array(
 					'form-field' => 'email',
 				)
@@ -3283,7 +3283,7 @@ function send_confirmation_on_profile_email() {
 		if ( email_exists( $_POST['email'] ) ) {
 			$errors->add(
 				'user_email',
-				__( '<strong>Error</strong>: The email address is already used.' ),
+				__( '<strong>Error:</strong> The email address is already used.' ),
 				array(
 					'form-field' => 'email',
 				)
diff --git a/src/wp-includes/wp-db.php b/src/wp-includes/wp-db.php
index 53ba207203..3d378f64db 100644
--- a/src/wp-includes/wp-db.php
+++ b/src/wp-includes/wp-db.php
@@ -3636,7 +3636,7 @@ class wpdb {
 		// Make sure the server has the required MySQL version.
 		if ( version_compare( $this->db_version(), $required_mysql_version, '<' ) ) {
 			/* translators: 1: WordPress version number, 2: Minimum required MySQL version number. */
-			return new WP_Error( 'database_version', sprintf( __( '<strong>Error</strong>: WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version ) );
+			return new WP_Error( 'database_version', sprintf( __( '<strong>Error:</strong> WordPress %1$s requires MySQL %2$s or higher' ), $wp_version, $required_mysql_version ) );
 		}
 	}
 
diff --git a/src/wp-login.php b/src/wp-login.php
index b7c14b4c83..4cb5ba1064 100644
--- a/src/wp-login.php
+++ b/src/wp-login.php
@@ -724,9 +724,9 @@ switch ( $action ) {
 
 		if ( isset( $_GET['error'] ) ) {
 			if ( 'invalidkey' === $_GET['error'] ) {
-				$errors->add( 'invalidkey', __( '<strong>Error</strong>: Your password reset link appears to be invalid. Please request a new link below.' ) );
+				$errors->add( 'invalidkey', __( '<strong>Error:</strong> Your password reset link appears to be invalid. Please request a new link below.' ) );
 			} elseif ( 'expiredkey' === $_GET['error'] ) {
-				$errors->add( 'expiredkey', __( '<strong>Error</strong>: Your password reset link has expired. Please request a new link below.' ) );
+				$errors->add( 'expiredkey', __( '<strong>Error:</strong> Your password reset link has expired. Please request a new link below.' ) );
 			}
 		}
 
@@ -842,7 +842,7 @@ switch ( $action ) {
 		$errors = new WP_Error();
 
 		if ( isset( $_POST['pass1'] ) && $_POST['pass1'] !== $_POST['pass2'] ) {
-			$errors->add( 'password_reset_mismatch', __( '<strong>Error</strong>: The passwords do not match.' ) );
+			$errors->add( 'password_reset_mismatch', __( '<strong>Error:</strong> The passwords do not match.' ) );
 		}
 
 		/**
@@ -1147,7 +1147,7 @@ switch ( $action ) {
 					'test_cookie',
 					sprintf(
 						/* translators: 1: Browser cookie documentation URL, 2: Support forums URL. */
-						__( '<strong>Error</strong>: Cookies are blocked due to unexpected output. For help, please see <a href="%1$s">this documentation</a> or try the <a href="%2$s">support forums</a>.' ),
+						__( '<strong>Error:</strong> Cookies are blocked due to unexpected output. For help, please see <a href="%1$s">this documentation</a> or try the <a href="%2$s">support forums</a>.' ),
 						__( 'https://wordpress.org/support/article/cookies/' ),
 						__( 'https://wordpress.org/support/forums/' )
 					)
@@ -1158,7 +1158,7 @@ switch ( $action ) {
 					'test_cookie',
 					sprintf(
 						/* translators: %s: Browser cookie documentation URL. */
-						__( '<strong>Error</strong>: Cookies are blocked or not supported by your browser. You must <a href="%s">enable cookies</a> to use WordPress.' ),
+						__( '<strong>Error:</strong> Cookies are blocked or not supported by your browser. You must <a href="%s">enable cookies</a> to use WordPress.' ),
 						__( 'https://wordpress.org/support/article/cookies/#enable-cookies-in-your-browser' )
 					)
 				);
@@ -1260,7 +1260,7 @@ switch ( $action ) {
 			if ( isset( $_GET['loggedout'] ) && $_GET['loggedout'] ) {
 				$errors->add( 'loggedout', __( 'You are now logged out.' ), 'message' );
 			} elseif ( isset( $_GET['registration'] ) && 'disabled' === $_GET['registration'] ) {
-				$errors->add( 'registerdisabled', __( '<strong>Error</strong>: User registration is currently not allowed.' ) );
+				$errors->add( 'registerdisabled', __( '<strong>Error:</strong> User registration is currently not allowed.' ) );
 			} elseif ( strpos( $redirect_to, 'about.php?updated' ) ) {
 				$errors->add( 'updated', __( '<strong>You have successfully updated WordPress!</strong> Please log back in to see what&#8217;s new.' ), 'message' );
 			} elseif ( WP_Recovery_Mode_Link_Service::LOGIN_ACTION_ENTERED === $action ) {
