diff --git a/README.md b/README.md
index 0c3362c6..1390edab 100644
--- a/README.md
+++ b/README.md
@@ -128,8 +128,6 @@ Before submitting design contributions, please discuss them with the Standard Eb
 
 ### Main website
 
-- Add type hints for class variables.
-
 - Convert ebooks from being stored in an APCu cache to our MariaDB database. (This is a big project!)
 
 - Creating a search bar for the SE Manual of Style.
@@ -186,7 +184,7 @@ Before submitting design contributions, please discuss them with the Standard Eb
 
 - Check for `null` using `===` and `!==`.
 
-- Where possible, include type hints for functions. Due to PHP limitations this may not always be possible, for example in cases where `null` may be passed or returned.
+- Where possible, include type hints for class properties and all functions.
 
 -   If using regex to parse HTML, use `|` as the regex delimiter instead of `/`.
 
diff --git a/lib/ArtworkTag.php b/lib/ArtworkTag.php
index 7a9f2dc5..f636230e 100644
--- a/lib/ArtworkTag.php
+++ b/lib/ArtworkTag.php
@@ -1,5 +1,4 @@
 <?
-
 class ArtworkTag extends Tag{
 	// *******
 	// GETTERS
@@ -19,11 +18,11 @@ class ArtworkTag extends Tag{
 	protected function Validate(): void{
 		$error = new Exceptions\ValidationException();
 
-		if($this->Name === null || strlen($this->Name) === 0){
+		if(strlen($this->Name) == 0){
 			$error->Add(new Exceptions\InvalidArtworkTagException());
 		}
 
-		if($this->Url === null || strlen($this->Url) === 0){
+		if($this->Url === null || strlen($this->Url) == 0){
 			$error->Add(new Exceptions\InvalidArtworkTagException());
 		}
 
diff --git a/lib/AtomFeed.php b/lib/AtomFeed.php
index 7bd56075..d8f457e8 100644
--- a/lib/AtomFeed.php
+++ b/lib/AtomFeed.php
@@ -1,16 +1,11 @@
 <?
 use Safe\DateTime;
 use function Safe\file_get_contents;
-use function Safe\file_put_contents;
-use function Safe\preg_replace;
-use function Safe\rename;
-use function Safe\tempnam;
-use function Safe\unlink;
 
 class AtomFeed extends Feed{
-	public $Id;
-	public $Updated = null;
-	public $Subtitle = null;
+	public string $Id;
+	public ?DateTime $Updated = null;
+	public ?string $Subtitle = null;
 
 	/**
 	 * @param string $title
@@ -26,7 +21,6 @@ class AtomFeed extends Feed{
 		$this->Stylesheet = SITE_URL . '/feeds/atom/style';
 	}
 
-
 	// *******
 	// METHODS
 	// *******
diff --git a/lib/Benefits.php b/lib/Benefits.php
index 230377c3..783e0192 100644
--- a/lib/Benefits.php
+++ b/lib/Benefits.php
@@ -1,8 +1,8 @@
 <?
 class Benefits{
-	public $CanAccessFeeds = false;
-	public $CanVote = false;
-	public $CanBulkDownload = false;
-	public $CanUploadArtwork = false;
-	public $CanReviewArtwork = false;
+	public bool $CanAccessFeeds = false;
+	public bool $CanVote = false;
+	public bool $CanBulkDownload = false;
+	public bool $CanUploadArtwork = false;
+	public bool $CanReviewArtwork = false;
 }
diff --git a/lib/Collection.php b/lib/Collection.php
index e2c455a1..7f09ba6d 100644
--- a/lib/Collection.php
+++ b/lib/Collection.php
@@ -1,12 +1,11 @@
 <?
-
 use function Safe\preg_replace;
 
 class Collection{
-	public $Name;
-	public $Url;
-	public $SequenceNumber = null;
-	public $Type = null;
+	public string $Name;
+	public string $Url;
+	public ?int $SequenceNumber = null;
+	public ?string $Type = null;
 
 	public function __construct(string $name){
 		$this->Name = $name;
diff --git a/lib/Contributor.php b/lib/Contributor.php
index 3cd85215..6748861b 100644
--- a/lib/Contributor.php
+++ b/lib/Contributor.php
@@ -1,12 +1,12 @@
 <?
 class Contributor{
-	public $Name;
-	public $UrlName;
-	public $SortName;
-	public $WikipediaUrl;
-	public $MarcRole;
-	public $FullName;
-	public $NacoafUrl;
+	public string $Name;
+	public string $UrlName;
+	public ?string $SortName;
+	public ?string $WikipediaUrl;
+	public ?string $MarcRole;
+	public ?string $FullName;
+	public ?string $NacoafUrl;
 
 	public function __construct(string $name, string $sortName = null, string $fullName = null, string $wikipediaUrl = null, string $marcRole = null, string $nacoafUrl = null){
 		$this->Name = str_replace('\'', '’', $name);
diff --git a/lib/Db.php b/lib/Db.php
index c2f63aa3..ecde9a93 100644
--- a/lib/Db.php
+++ b/lib/Db.php
@@ -1,5 +1,4 @@
 <?
-
 class Db{
 	public static function GetLastInsertedId(): int{
 		return $GLOBALS['DbConnection']->GetLastInsertedId();
diff --git a/lib/DbConnection.php b/lib/DbConnection.php
index 2577edbb..f06c5f33 100644
--- a/lib/DbConnection.php
+++ b/lib/DbConnection.php
@@ -4,10 +4,9 @@ use function Safe\preg_match;
 use function Safe\posix_getpwuid;
 
 class DbConnection{
-	private $_link = null;
-	public $IsConnected = false;
-	public $QueryCount = 0;
-	public $LastQueryAffectedRowCount = 0;
+	private ?\PDO $_link = null;
+	public int $QueryCount = 0;
+	public int $LastQueryAffectedRowCount = 0;
 
 	public function __construct(?string $defaultDatabase = null, string $host = 'localhost', ?string $user = null, string$password = '', bool $forceUtf8 = true, bool $require = true){
 		if($user === null){
@@ -51,8 +50,6 @@ class DbConnection{
 
 			// We can't use persistent connections (connection pooling) because we would have race condition problems with last_insert_id()
 			$this->_link = new \PDO($connectionString, $user, $password, $params);
-
-			$this->IsConnected = true;
 		}
 		catch(Exception $ex){
 			if(SITE_STATUS == SITE_STATUS_DEV){
@@ -79,7 +76,7 @@ class DbConnection{
 	* @return Array<mixed>
 	*/
 	public function Query(string $sql, array $params = [], string $class = 'stdClass'): array{
-		if(!$this->IsConnected){
+		if($this->_link === null){
 			return [];
 		}
 
@@ -245,8 +242,19 @@ class DbConnection{
 
 	// Gets the last auto-increment id
 	public function GetLastInsertedId(): ?int{
+		if($this->_link === null){
+			return null;
+		}
+
 		$id = $this->_link->lastInsertId();
 
+		if($id === false){
+			return null;
+		}
+		else{
+			$id = (int)$id;
+		}
+
 		if($id == 0){
 			return null;
 		}
diff --git a/lib/Ebook.php b/lib/Ebook.php
index be61608c..ca191246 100644
--- a/lib/Ebook.php
+++ b/lib/Ebook.php
@@ -10,58 +10,70 @@ use function Safe\sprintf;
 use function Safe\shell_exec;
 use function Safe\substr;
 
+/**
+ * @property array<GitCommit> $GitCommits
+ * @property array<EbookTag> $EbookTags
+ * @property array<string> $LocTags
+ * @property array<Collection> $Collections
+ * @property array<EbookSource> $Sources
+ * @property array<Contributor> $Authors
+ * @property array<Contributor> $Illustrators
+ * @property array<Contributor> $Translators
+ * @property array<Contributor> $Contributors
+ * @property ?array<string> $TocEntries
+ */
 class Ebook{
-	public $WwwFilesystemPath;
-	public $RepoFilesystemPath;
-	public $Url;
-	public $KindleCoverUrl;
-	public $EpubUrl;
-	public $AdvancedEpubUrl;
-	public $KepubUrl;
-	public $Azw3Url;
-	public $HasDownloads;
+	public string $WwwFilesystemPath;
+	public string $RepoFilesystemPath;
+	public string $Url;
+	public string $KindleCoverUrl;
+	public string $EpubUrl;
+	public string $AdvancedEpubUrl;
+	public string $KepubUrl;
+	public string $Azw3Url;
+	public bool $HasDownloads;
 	public $GitCommits = [];
 	public $Tags = [];
 	public $LocTags = [];
 	public $Collections = [];
-	public $Identifier;
-	public $UrlSafeIdentifier;
-	public $HeroImageUrl;
-	public $HeroImageAvifUrl;
-	public $HeroImage2xUrl;
-	public $HeroImage2xAvifUrl;
-	public $CoverImageUrl;
-	public $CoverImageAvifUrl;
-	public $CoverImage2xUrl;
-	public $CoverImage2xAvifUrl;
-	public $DistCoverUrl;
-	public $Title;
-	public $FullTitle;
-	public $AlternateTitle;
-	public $Description;
-	public $LongDescription;
-	public $Language;
-	public $WordCount;
-	public $ReadingEase;
-	public $ReadingEaseDescription;
-	public $ReadingTime;
-	public $GitHubUrl;
-	public $WikipediaUrl;
+	public string $Identifier;
+	public string $UrlSafeIdentifier;
+	public string $HeroImageUrl;
+	public string $HeroImageAvifUrl;
+	public string $HeroImage2xUrl;
+	public string $HeroImage2xAvifUrl;
+	public string $CoverImageUrl;
+	public string $CoverImageAvifUrl;
+	public string $CoverImage2xUrl;
+	public string $CoverImage2xAvifUrl;
+	public string $DistCoverUrl;
+	public ?string $Title = null;
+	public ?string $FullTitle = null;
+	public ?string $AlternateTitle = null;
+	public ?string $Description = null;
+	public ?string $LongDescription = null;
+	public ?string $Language = null;
+	public int $WordCount;
+	public float $ReadingEase;
+	public string $ReadingEaseDescription;
+	public string $ReadingTime;
+	public ?string $GitHubUrl = null;
+	public ?string $WikipediaUrl = null;
 	public $Sources = [];
-	public $Authors = []; // Array of Contributors
-	public $AuthorsHtml;
-	public $AuthorsUrl; // This is a single URL even if there are multiple authors; for example, /ebooks/karl-marx_friedrich-engels/
-	public $Illustrators = []; // Array of Contributors
-	public $Translators = []; // Array of Contributors
-	public $Contributors = []; // Array of Contributors
-	public $ContributorsHtml;
-	public $TitleWithCreditsHtml = '';
-	public $Created;
-	public $Updated;
-	public $TextUrl;
-	public $TextSinglePageUrl;
-	public $TextSinglePageSizeNumber = null;
-	public $TextSinglePageSizeUnit = null;
+	public $Authors = [];
+	public string $AuthorsHtml;
+	public string $AuthorsUrl; // This is a single URL even if there are multiple authors; for example, /ebooks/karl-marx_friedrich-engels/
+	public $Illustrators = [];
+	public $Translators = [];
+	public $Contributors = [];
+	public ?string $ContributorsHtml = null;
+	public string $TitleWithCreditsHtml = '';
+	public DateTime $Created;
+	public DateTime $Updated;
+	public string $TextUrl;
+	public string $TextSinglePageUrl;
+	public ?string $TextSinglePageSizeNumber = null;
+	public ?string $TextSinglePageSizeUnit = null;
 	public $TocEntries = null; // A list of non-Roman ToC entries ONLY IF the work has the 'se:is-a-collection' metadata element, null otherwise
 
 	public function __construct(?string $wwwFilesystemPath = null){
@@ -384,7 +396,7 @@ class Ebook{
 
 		// Figure out the reading time.
 		$readingTime = ceil($this->WordCount / AVERAGE_READING_WORDS_PER_MINUTE);
-		$this->ReadingTime = $readingTime;
+		$this->ReadingTime = (string)$readingTime;
 
 		if($readingTime < 60){
 			$this->ReadingTime .= ' minute';
diff --git a/lib/EbookSource.php b/lib/EbookSource.php
index 98aeb091..81ac892e 100644
--- a/lib/EbookSource.php
+++ b/lib/EbookSource.php
@@ -1,7 +1,7 @@
 <?
 class EbookSource{
-	public $Type;
-	public $Url;
+	public int $Type;
+	public string $Url;
 
 	public function __construct(int $type, string $url){
 		$this->Type = $type;
diff --git a/lib/EbookTag.php b/lib/EbookTag.php
index 0091fc8c..d54a2760 100644
--- a/lib/EbookTag.php
+++ b/lib/EbookTag.php
@@ -6,7 +6,6 @@ class EbookTag extends Tag{
 		$this->_Url = '/subjects/' . $this->UrlName;
 	}
 
-
 	// *******
 	// GETTERS
 	// *******
diff --git a/lib/Email.php b/lib/Email.php
index f7465bcf..01ab1fc1 100644
--- a/lib/Email.php
+++ b/lib/Email.php
@@ -2,20 +2,20 @@
 use PHPMailer\PHPMailer\PHPMailer;
 use PHPMailer\PHPMailer\Exception;
 
-use function Safe\define;
-use function Safe\file_get_contents;
-
+/**
+ * @property array<array<string>> $Attachments
+ */
 class Email{
-	public $To = '';
-	public $ToName = '';
-	public $From = '';
-	public $FromName = '';
-	public $ReplyTo = '';
-	public $Subject = '';
-	public $Body = '';
-	public $TextBody = '';
+	public string $To = '';
+	public string $ToName = '';
+	public string $From = '';
+	public string $FromName = '';
+	public string $ReplyTo = '';
+	public string $Subject = '';
+	public string $Body = '';
+	public string $TextBody = '';
 	public $Attachments = [];
-	public $PostmarkStream = null;
+	public ?string $PostmarkStream = null;
 
 	public function __construct(bool $isNoReplyEmail = false){
 		if($isNoReplyEmail){
@@ -35,7 +35,7 @@ class Email{
 			$this->ReplyTo = $this->From;
 		}
 
-		if($this->To === null || $this->To == ''){
+		if($this->To == ''){
 			return false;
 		}
 
diff --git a/lib/Feed.php b/lib/Feed.php
index 50526aa3..063c7633 100644
--- a/lib/Feed.php
+++ b/lib/Feed.php
@@ -1,18 +1,20 @@
 <?
-use Safe\DateTime;
 use function Safe\exec;
 use function Safe\file_get_contents;
 use function Safe\file_put_contents;
 use function Safe\tempnam;
 use function Safe\unlink;
 
+/**
+ * @param array<string> $Entries
+ */
 class Feed{
-	public $Url;
-	public $Title;
+	public string $Url;
+	public string $Title;
 	public $Entries = [];
-	public $Path = null;
-	public $Stylesheet = null;
-	protected $XmlString = null;
+	public string $Path;
+	public ?string $Stylesheet = null;
+	protected ?string $XmlString = null;
 
 	/**
 	 * @param string $title
diff --git a/lib/GitCommit.php b/lib/GitCommit.php
index 7cfa3750..15fea568 100644
--- a/lib/GitCommit.php
+++ b/lib/GitCommit.php
@@ -2,9 +2,9 @@
 use Safe\DateTimeImmutable;
 
 class GitCommit{
-	public $Created;
-	public $Message;
-	public $Hash;
+	public DateTimeImmutable $Created;
+	public string $Message;
+	public string $Hash;
 
 	public function __construct(string $unixTimestamp, string $hash, string $message){
 		$this->Created = new DateTimeImmutable('@' . $unixTimestamp);
diff --git a/lib/Image.php b/lib/Image.php
index 6bb38c79..1b233879 100644
--- a/lib/Image.php
+++ b/lib/Image.php
@@ -7,8 +7,8 @@ use function Safe\getimagesize;
 use function Safe\unlink;
 
 class Image{
-	public $Path;
-	public $MimeType;
+	public string $Path;
+	public ?ImageMimeType $MimeType;
 
 	public function __construct(string $path){
 		$this->Path = $path;
diff --git a/lib/Library.php b/lib/Library.php
index 937d6c18..79c50625 100644
--- a/lib/Library.php
+++ b/lib/Library.php
@@ -7,14 +7,11 @@ use function Safe\filesize;
 use function Safe\glob;
 use function Safe\gmdate;
 use function Safe\ksort;
-use function Safe\preg_match;
 use function Safe\preg_replace;
 use function Safe\shell_exec;
 use function Safe\sleep;
-use function Safe\sort;
 use function Safe\usort;
 
-
 class Library{
 	/**
 	* @param string $query
diff --git a/lib/Log.php b/lib/Log.php
index 4fc68c1a..ff77e6ab 100644
--- a/lib/Log.php
+++ b/lib/Log.php
@@ -7,8 +7,8 @@ use function Safe\gmdate;
 use function Safe\substr;
 
 class Log{
-	private $RequestId = null;
-	private $LogFilePath = null;
+	private string $RequestId;
+	private ?string $LogFilePath = null;
 
 	public function __construct(?string $logFilePath){
 		// Get a semi-random ID to identify this request within the log.
diff --git a/lib/Museum.php b/lib/Museum.php
index 7cd45752..af076900 100644
--- a/lib/Museum.php
+++ b/lib/Museum.php
@@ -1,9 +1,8 @@
 <?
-
 class Museum extends PropertiesBase{
-	public $MuseumId;
-	public $Name;
-	public $Domain;
+	public int $MuseumId;
+	public string $Name;
+	public string $Domain;
 
 	public static function GetByUrl(?string $url): Museum{
 		if($url === null){
diff --git a/lib/NewsletterSubscription.php b/lib/NewsletterSubscription.php
index e56cec14..cf9f7059 100644
--- a/lib/NewsletterSubscription.php
+++ b/lib/NewsletterSubscription.php
@@ -6,12 +6,12 @@ use Safe\DateTime;
  * @property string $Url
  */
 class NewsletterSubscription extends PropertiesBase{
-	public $IsConfirmed = false;
-	public $IsSubscribedToSummary;
-	public $IsSubscribedToNewsletter;
-	public $UserId;
+	public bool $IsConfirmed = false;
+	public bool $IsSubscribedToSummary;
+	public bool $IsSubscribedToNewsletter;
+	public int $UserId;
+	public DateTime $Created;
 	protected $_User;
-	public $Created;
 	protected $_Url = null;
 
 	// *******
@@ -85,8 +85,8 @@ class NewsletterSubscription extends PropertiesBase{
 	public function SendConfirmationEmail(): void{
 		$em = new Email(true);
 		$em->PostmarkStream = EMAIL_POSTMARK_STREAM_BROADCAST;
-		$em->To = $this->User->Email;
-		if($this->User->Name != ''){
+		$em->To = $this->User->Email ?? '';
+		if($this->User->Name !== null && $this->User->Name != ''){
 			$em->ToName = $this->User->Name;
 		}
 		$em->Subject = 'Action required: confirm your newsletter subscription';
diff --git a/lib/OpdsAcquisitionFeed.php b/lib/OpdsAcquisitionFeed.php
index ef5f46c4..9089c3ed 100644
--- a/lib/OpdsAcquisitionFeed.php
+++ b/lib/OpdsAcquisitionFeed.php
@@ -2,7 +2,7 @@
 use Safe\DateTime;
 
 class OpdsAcquisitionFeed extends OpdsFeed{
-	public $IsCrawlable;
+	public bool $IsCrawlable;
 
 	public function __construct(string $title, string $subtitle, string $url, string $path, array $entries, ?OpdsNavigationFeed $parent, bool $isCrawlable = false){
 		parent::__construct($title, $subtitle, $url, $path, $entries, $parent);
diff --git a/lib/OpdsFeed.php b/lib/OpdsFeed.php
index 581ffb07..d30ab1b7 100644
--- a/lib/OpdsFeed.php
+++ b/lib/OpdsFeed.php
@@ -3,7 +3,7 @@ use Safe\DateTime;
 use function Safe\file_put_contents;
 
 class OpdsFeed extends AtomFeed{
-	public $Parent = null; // OpdsNavigationFeed class
+	public ?OpdsNavigationFeed $Parent = null;
 
 	/**
 	 * @param string $title
diff --git a/lib/OpdsNavigationEntry.php b/lib/OpdsNavigationEntry.php
index a56a36ee..eb409dc3 100644
--- a/lib/OpdsNavigationEntry.php
+++ b/lib/OpdsNavigationEntry.php
@@ -1,13 +1,13 @@
 <?
 class OpdsNavigationEntry{
-	public $Id;
-	public $Url;
-	public $Rel;
-	public $Type;
-	public $Updated;
-	public $Description;
-	public $Title;
-	public $SortTitle;
+	public string $Id;
+	public string $Url;
+	public string $Rel;
+	public string $Type;
+	public ?DateTime $Updated;
+	public string $Description;
+	public string $Title;
+	public string $SortTitle;
 
 	public function __construct(string $title, string $description, string $url, ?DateTime $updated, string $rel, string $type){
 		$this->Id = SITE_URL . $url;
diff --git a/lib/OpdsNavigationFeed.php b/lib/OpdsNavigationFeed.php
index f427c577..128c11fe 100644
--- a/lib/OpdsNavigationFeed.php
+++ b/lib/OpdsNavigationFeed.php
@@ -1,6 +1,5 @@
 <?
 use Safe\DateTime;
-
 use function Safe\file_get_contents;
 
 class OpdsNavigationFeed extends OpdsFeed{
diff --git a/lib/Patron.php b/lib/Patron.php
index 9065e9cd..756b575c 100644
--- a/lib/Patron.php
+++ b/lib/Patron.php
@@ -5,13 +5,13 @@ use Safe\DateTime;
  * @property User $User
  */
 class Patron extends PropertiesBase{
-	public $UserId = null;
+	public ?int $UserId = null;
 	protected $_User = null;
-	public $IsAnonymous;
-	public $AlternateName;
-	public $IsSubscribedToEmails;
-	public $Created = null;
-	public $Ended = null;
+	public bool $IsAnonymous;
+	public ?string $AlternateName;
+	public bool $IsSubscribedToEmails;
+	public ?DateTime $Created = null;
+	public ?DateTime $Ended = null;
 
 
 	// *******
@@ -54,8 +54,8 @@ class Patron extends PropertiesBase{
 	private function SendWelcomeEmail(bool $isReturning): void{
 		if($this->User !== null){
 			$em = new Email();
-			$em->To = $this->User->Email;
-			$em->ToName = $this->User->Name;
+			$em->To = $this->User->Email ?? '';
+			$em->ToName = $this->User->Name ?? '';
 			$em->From = EDITOR_IN_CHIEF_EMAIL_ADDRESS;
 			$em->FromName = EDITOR_IN_CHIEF_NAME;
 			$em->Subject = 'Thank you for supporting Standard Ebooks!';
diff --git a/lib/Payment.php b/lib/Payment.php
index cf14dda0..0882c3a4 100644
--- a/lib/Payment.php
+++ b/lib/Payment.php
@@ -1,19 +1,18 @@
 <?
-
 /**
  * @property User $User
  */
 class Payment extends PropertiesBase{
-	public $PaymentId;
-	public $UserId = null;
-	protected $_User = null;
-	public $Created;
-	public $ChannelId;
-	public $TransactionId;
-	public $Amount;
-	public $Fee;
-	public $IsRecurring;
-	public $IsMatchingDonation = false;
+	public int $PaymentId;
+	public ?int $UserId = null;
+	public DateTime $Created;
+	public int $ChannelId;
+	public string $TransactionId;
+	public float $Amount;
+	public float $Fee;
+	public bool $IsRecurring;
+	public bool $IsMatchingDonation = false;
+	protected ?User $_User = null;
 
 
 	// *******
diff --git a/lib/Poll.php b/lib/Poll.php
index 8bea0f7a..e0e1277d 100644
--- a/lib/Poll.php
+++ b/lib/Poll.php
@@ -3,23 +3,25 @@ use Safe\DateTime;
 use function Safe\usort;
 
 /**
+ * @property ?array<PollItem> $_PollItems
+ * @property ?array<PollItem> $_PollItemsByWinner
  * @property string $Url
  * @property array<PollItem> $PollItems
  * @property array<PollItem> $PollItemsByWinner
  * @property int $VoteCount
  */
 class Poll extends PropertiesBase{
-	public $PollId;
-	public $Name;
-	public $UrlName;
-	public $Description;
-	public $Created;
-	public $Start;
-	public $End;
-	protected $_Url = null;
+	public int $PollId;
+	public string $Name;
+	public string $UrlName;
+	public string $Description;
+	public DateTime $Created;
+	public DateTime $Start;
+	public DateTime $End;
+	protected ?string $_Url = null;
 	protected $_PollItems = null;
 	protected $_PollItemsByWinner = null;
-	protected $_VoteCount = null;
+	protected ?int $_VoteCount = null;
 
 
 	// *******
@@ -71,7 +73,7 @@ class Poll extends PropertiesBase{
 			$this->_PollItemsByWinner = $this->PollItems;
 			usort($this->_PollItemsByWinner, function(PollItem $a, PollItem $b){ return $a->VoteCount <=> $b->VoteCount; });
 
-			$this->_PollItemsByWinner = array_reverse($this->_PollItemsByWinner);
+			$this->_PollItemsByWinner = array_reverse($this->_PollItemsByWinner ?? []);
 		}
 
 		return $this->_PollItemsByWinner;
diff --git a/lib/PollItem.php b/lib/PollItem.php
index cf9ce783..6b56387a 100644
--- a/lib/PollItem.php
+++ b/lib/PollItem.php
@@ -1,16 +1,15 @@
 <?
-
 /**
  * @property int $VoteCount
  * @property Poll $Poll
  */
 class PollItem extends PropertiesBase{
-	public $PollItemId;
-	public $PollId;
-	public $Name;
-	public $Description;
-	protected $_VoteCount = null;
-	protected $_Poll = null;
+	public int $PollItemId;
+	public int $PollId;
+	public string $Name;
+	public string $Description;
+	protected ?int $_VoteCount = null;
+	protected ?Poll $_Poll = null;
 
 
 	// *******
diff --git a/lib/PollVote.php b/lib/PollVote.php
index d34ddfcf..b4cb0203 100644
--- a/lib/PollVote.php
+++ b/lib/PollVote.php
@@ -7,12 +7,12 @@ use Safe\DateTime;
  * @property string $Url
  */
 class PollVote extends PropertiesBase{
-	public $UserId;
-	protected $_User = null;
-	public $Created;
-	public $PollItemId;
-	protected $_PollItem = null;
-	protected $_Url = null;
+	public int $UserId;
+	public DateTime $Created;
+	public ?int $PollItemId = null;
+	protected ?User $_User = null;
+	protected ?PollItem $_PollItem = null;
+	protected ?string $_Url = null;
 
 
 	// *******
@@ -35,7 +35,7 @@ class PollVote extends PropertiesBase{
 	protected function Validate(): void{
 		$error = new Exceptions\ValidationException();
 
-		if($this->UserId === null || $this->User === null){
+		if($this->User === null){
 			$error->Add(new Exceptions\InvalidUserException());
 		}
 
diff --git a/lib/PropertiesBase.php b/lib/PropertiesBase.php
index 0b3c0518..1f937524 100644
--- a/lib/PropertiesBase.php
+++ b/lib/PropertiesBase.php
@@ -1,6 +1,4 @@
 <?
-use function Safe\substr;
-
 abstract class PropertiesBase{
 	/**
 	* @return mixed
diff --git a/lib/RssFeed.php b/lib/RssFeed.php
index 9fba0acd..b59507eb 100644
--- a/lib/RssFeed.php
+++ b/lib/RssFeed.php
@@ -5,7 +5,7 @@ use function Safe\filesize;
 use function Safe\preg_replace;
 
 class RssFeed extends Feed{
-	public $Description;
+	public string $Description;
 
 	/**
 	 * @param string $title
diff --git a/lib/Session.php b/lib/Session.php
index 389a450f..22706b08 100644
--- a/lib/Session.php
+++ b/lib/Session.php
@@ -8,11 +8,11 @@ use function Safe\strtotime;
  * @property string $Url
  */
 class Session extends PropertiesBase{
-	public $UserId;
-	protected $_User = null;
-	public $Created;
-	public $SessionId;
-	public $_Url;
+	public int $UserId;
+	protected ?User $_User = null;
+	public DateTime $Created;
+	public string $SessionId;
+	public ?string $_Url = null;
 
 
 	// *******
diff --git a/lib/Tag.php b/lib/Tag.php
index 2060702b..91cb2b9c 100644
--- a/lib/Tag.php
+++ b/lib/Tag.php
@@ -1,11 +1,10 @@
 <?
-
 /**
  * @property string $Url
  */
 class Tag extends PropertiesBase{
-	public $TagId;
-	public $Name;
-	public $UrlName;
-	protected $_Url;
+	public int $TagId;
+	public string $Name;
+	public string $UrlName;
+	protected ?string $_Url;
 }
diff --git a/lib/User.php b/lib/User.php
index 060ba8a6..354b1032 100644
--- a/lib/User.php
+++ b/lib/User.php
@@ -4,19 +4,20 @@ use Safe\DateTime;
 
 /**
  * @property Array<Payment> $Payments
+ * @property ?bool $IsRegistered
  * @property Benefits $Benefits
+ * @property ?array<Payment> $_Payments
  */
 class User extends PropertiesBase{
-	public $UserId;
-	public $Name;
-	public $Email;
-	public $Created;
-	public $Uuid;
-	public $PasswordHash;
-	protected $_IsRegistered = null;
+	public int $UserId;
+	public ?string $Name;
+	public ?string $Email;
+	public DateTime $Created;
+	public string $Uuid;
+	public ?string $PasswordHash;
+	protected ?bool $_IsRegistered = null;
 	protected $_Payments = null;
-	protected $_Benefits = null;
-
+	protected ?Benefits $_Benefits = null;
 
 	// *******
 	// GETTERS
@@ -59,7 +60,7 @@ class User extends PropertiesBase{
 		return $this->_Benefits;
 	}
 
-	protected function GetIsRegistered(): bool{
+	protected function GetIsRegistered(): ?bool{
 		if($this->_IsRegistered === null){
 			// A user is "registered" if they have a benefits entry in the table.
 			// This function will fill it out for us.
diff --git a/www/newsletter/subscriptions/post.php b/www/newsletter/subscriptions/post.php
index f056992c..a3f841c4 100644
--- a/www/newsletter/subscriptions/post.php
+++ b/www/newsletter/subscriptions/post.php
@@ -35,8 +35,8 @@ if(HttpInput::Str(POST, 'automationtest', false)){
 try{
 	$subscription->User = new User();
 	$subscription->User->Email = HttpInput::Str(POST, 'email', false);
-	$subscription->IsSubscribedToNewsletter = HttpInput::Bool(POST, 'issubscribedtonewsletter', false);
-	$subscription->IsSubscribedToSummary = HttpInput::Bool(POST, 'issubscribedtosummary', false);
+	$subscription->IsSubscribedToNewsletter = HttpInput::Bool(POST, 'issubscribedtonewsletter') ?? false;
+	$subscription->IsSubscribedToSummary = HttpInput::Bool(POST, 'issubscribedtosummary') ?? false;
 
 	$captcha = HttpInput::Str(SESSION, 'captcha', false) ?? '';
 
diff --git a/www/polls/votes/post.php b/www/polls/votes/post.php
index 1be01702..9e6f3484 100644
--- a/www/polls/votes/post.php
+++ b/www/polls/votes/post.php
@@ -1,5 +1,4 @@
 <?
-use function Safe\preg_match;
 use function Safe\session_unset;
 
 if(HttpInput::RequestMethod() != HTTP_POST){