diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5cc851c5..891adc8a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,10 +7,29 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Added
 
+- Methods `getLineNumber` and `getColumnNumber` which return a nullable `int`
+  for the following classes:
+  `Comment`, `CSSList`, `SourceException`, `Charset`, `CSSNamespace`, `Import`,
+  `Rule`, `DeclarationBlock`, `RuleSet`, `CSSFunction`, `Value` (#1225)
+- `Positionable` interface for CSS items that may have a position
+  (line and perhaps column number) in the parsed CSS (#1221)
+
 ### Changed
 
+- Implement `Positionable` in the following CSS item classes:
+  `Comment`, `CSSList`, `SourceException`, `Charset`, `CSSNamespace`, `Import`,
+  `Rule`, `DeclarationBlock`, `RuleSet`, `CSSFunction`, `Value` (#1225)
+
 ### Deprecated
 
+- `getLineNo()` is deprecated in these classes (use `getLineNumber()` instead):
+  `Comment`, `CSSList`, `SourceException`, `Charset`, `CSSNamespace`, `Import`,
+  `Rule`, `DeclarationBlock`, `RuleSet`, `CSSFunction`, `Value` (#1225, #1233)
+- `Rule::getColNo()` is deprecated (use `getColumnNumber()` instead)
+  (#1225, #1233)
+- Providing zero as the line number argument to `Rule::setPosition()` is
+  deprecated (pass `null` instead if there is no line number) (#1225, #1233)
+
 ### Removed
 
 ### Fixed
diff --git a/composer.json b/composer.json
index acf650a2..e3caf0cc 100644
--- a/composer.json
+++ b/composer.json
@@ -27,7 +27,8 @@
         "ext-iconv": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "5.7.27 || 6.5.14 || 7.5.20 || 8.5.41"
+        "phpunit/phpunit": "5.7.27 || 6.5.14 || 7.5.20 || 8.5.41",
+        "rawr/cross-data-providers": "^2.0.0"
     },
     "suggest": {
         "ext-mbstring": "for parsing UTF-8 CSS"
diff --git a/src/CSSList/CSSList.php b/src/CSSList/CSSList.php
index 0f40d40a..2156aa11 100644
--- a/src/CSSList/CSSList.php
+++ b/src/CSSList/CSSList.php
@@ -9,6 +9,8 @@
 use Sabberworm\CSS\Parsing\SourceException;
 use Sabberworm\CSS\Parsing\UnexpectedEOFException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Property\AtRule;
 use Sabberworm\CSS\Property\Charset;
 use Sabberworm\CSS\Property\CSSNamespace;
@@ -29,8 +31,10 @@
  *
  * It can also contain `Import` and `Charset` objects stemming from at-rules.
  */
-abstract class CSSList implements Renderable, Commentable
+abstract class CSSList implements Commentable, Positionable, Renderable
 {
+    use Position;
+
     /**
      * @var array<array-key, Comment>
      *
@@ -45,13 +49,6 @@ abstract class CSSList implements Renderable, Commentable
      */
     protected $aContents;
 
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iLineNo;
-
     /**
      * @param int $iLineNo
      */
@@ -59,7 +56,7 @@ public function __construct($iLineNo = 0)
     {
         $this->aComments = [];
         $this->aContents = [];
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
     }
 
     /**
@@ -258,14 +255,6 @@ private static function identifierIs($sIdentifier, $sMatch)
             ?: preg_match("/^(-\\w+-)?$sMatch$/i", $sIdentifier) === 1;
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * Prepends an item to the list of contents.
      *
diff --git a/src/Comment/Comment.php b/src/Comment/Comment.php
index 1d8810ec..fb571b40 100644
--- a/src/Comment/Comment.php
+++ b/src/Comment/Comment.php
@@ -4,15 +4,12 @@
 
 use Sabberworm\CSS\OutputFormat;
 use Sabberworm\CSS\Renderable;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 
-class Comment implements Renderable
+class Comment implements Positionable, Renderable
 {
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iLineNo;
+    use Position;
 
     /**
      * @var string
@@ -28,7 +25,7 @@ class Comment implements Renderable
     public function __construct($sComment = '', $iLineNo = 0)
     {
         $this->sComment = $sComment;
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
     }
 
     /**
@@ -39,14 +36,6 @@ public function getComment()
         return $this->sComment;
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * @param string $sComment
      *
diff --git a/src/Parsing/SourceException.php b/src/Parsing/SourceException.php
index 1ca668a9..1aa27b43 100644
--- a/src/Parsing/SourceException.php
+++ b/src/Parsing/SourceException.php
@@ -2,12 +2,12 @@
 
 namespace Sabberworm\CSS\Parsing;
 
-class SourceException extends \Exception
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
+
+class SourceException extends \Exception implements Positionable
 {
-    /**
-     * @var int
-     */
-    private $iLineNo;
+    use Position;
 
     /**
      * @param string $sMessage
@@ -15,18 +15,10 @@ class SourceException extends \Exception
      */
     public function __construct($sMessage, $iLineNo = 0)
     {
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
         if (!empty($iLineNo)) {
             $sMessage .= " [line no: $iLineNo]";
         }
         parent::__construct($sMessage);
     }
-
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
 }
diff --git a/src/Position/Position.php b/src/Position/Position.php
new file mode 100644
index 00000000..1c4d0df0
--- /dev/null
+++ b/src/Position/Position.php
@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Position;
+
+/**
+ * Provides a standard reusable implementation of `Positionable`.
+ *
+ * @internal
+ *
+ * @phpstan-require-implements Positionable
+ */
+trait Position
+{
+    /**
+     * @var int<1, max>|null
+     */
+    protected $lineNumber;
+
+    /**
+     * @var int<0, max>|null
+     */
+    protected $columnNumber;
+
+    /**
+     * @return int<1, max>|null
+     */
+    public function getLineNumber()
+    {
+        return $this->lineNumber;
+    }
+
+    /**
+     * @return int<0, max>
+     */
+    public function getLineNo()
+    {
+        $lineNumber = $this->getLineNumber();
+
+        return $lineNumber !== null ? $lineNumber : 0;
+    }
+
+    /**
+     * @return int<0, max>|null
+     */
+    public function getColumnNumber()
+    {
+        return $this->columnNumber;
+    }
+
+    /**
+     * @return int<0, max>
+     */
+    public function getColNo()
+    {
+        $columnNumber = $this->getColumnNumber();
+
+        return $columnNumber !== null ? $columnNumber : 0;
+    }
+
+    /**
+     * @param int<0, max>|null $lineNumber
+     * @param int<0, max>|null $columnNumber
+     */
+    public function setPosition($lineNumber, $columnNumber = null)
+    {
+        // The conditional is for backwards compatibility (backcompat); `0` will not be allowed in future.
+        $this->lineNumber = $lineNumber !== 0 ? $lineNumber : null;
+        $this->columnNumber = $columnNumber;
+    }
+}
diff --git a/src/Position/Positionable.php b/src/Position/Positionable.php
new file mode 100644
index 00000000..4539c425
--- /dev/null
+++ b/src/Position/Positionable.php
@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Position;
+
+/**
+ * Represents a CSS item that may have a position in the source CSS document (line number and possibly column number).
+ *
+ * A standard implementation of this interface is available in the `Position` trait.
+ */
+interface Positionable
+{
+    /**
+     * @return int<1, max>|null
+     */
+    public function getLineNumber();
+
+    /**
+     * @return int<0, max>
+     *
+     * @deprecated in version 8.9.0, will be removed in v9.0. Use `getLineNumber()` instead.
+     */
+    public function getLineNo();
+
+    /**
+     * @return int<0, max>|null
+     */
+    public function getColumnNumber();
+
+    /**
+     * @return int<0, max>
+     *
+     * @deprecated in version 8.9.0, will be removed in v9.0. Use `getColumnNumber()` instead.
+     */
+    public function getColNo();
+
+    /**
+     * @param int<0, max>|null $lineNumber
+     *        Providing zero for this parameter is deprecated in version 8.9.0, and will not be supported from v9.0.
+     *        Use `null` instead when no line number is available.
+     * @param int<0, max>|null $columnNumber
+     */
+    public function setPosition($lineNumber, $columnNumber = null);
+}
diff --git a/src/Property/CSSNamespace.php b/src/Property/CSSNamespace.php
index 0d90cc3b..188d3581 100644
--- a/src/Property/CSSNamespace.php
+++ b/src/Property/CSSNamespace.php
@@ -4,12 +4,16 @@
 
 use Sabberworm\CSS\Comment\Comment;
 use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 
 /**
  * `CSSNamespace` represents an `@namespace` rule.
  */
-class CSSNamespace implements AtRule
+class CSSNamespace implements AtRule, Positionable
 {
+    use Position;
+
     /**
      * @var string
      */
@@ -41,18 +45,10 @@ public function __construct($mUrl, $sPrefix = null, $iLineNo = 0)
     {
         $this->mUrl = $mUrl;
         $this->sPrefix = $sPrefix;
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
         $this->aComments = [];
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * @return string
      *
diff --git a/src/Property/Charset.php b/src/Property/Charset.php
index de9016ad..1ebff3f3 100644
--- a/src/Property/Charset.php
+++ b/src/Property/Charset.php
@@ -4,6 +4,8 @@
 
 use Sabberworm\CSS\Comment\Comment;
 use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Value\CSSString;
 
 /**
@@ -14,8 +16,10 @@
  * - May only appear at the very top of a Document’s contents.
  * - Must not appear more than once.
  */
-class Charset implements AtRule
+class Charset implements AtRule, Positionable
 {
+    use Position;
+
     /**
      * @var CSSString
      */
@@ -42,18 +46,10 @@ class Charset implements AtRule
     public function __construct(CSSString $oCharset, $iLineNo = 0)
     {
         $this->oCharset = $oCharset;
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
         $this->aComments = [];
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * @param string|CSSString $oCharset
      *
diff --git a/src/Property/Import.php b/src/Property/Import.php
index e3f10474..5b474493 100644
--- a/src/Property/Import.php
+++ b/src/Property/Import.php
@@ -4,13 +4,17 @@
 
 use Sabberworm\CSS\Comment\Comment;
 use Sabberworm\CSS\OutputFormat;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Value\URL;
 
 /**
  * Class representing an `@import` rule.
  */
-class Import implements AtRule
+class Import implements AtRule, Positionable
 {
+    use Position;
+
     /**
      * @var URL
      */
@@ -21,13 +25,6 @@ class Import implements AtRule
      */
     private $sMediaQuery;
 
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iLineNo;
-
     /**
      * @var array<array-key, Comment>
      *
@@ -44,18 +41,10 @@ public function __construct(URL $oLocation, $sMediaQuery, $iLineNo = 0)
     {
         $this->oLocation = $oLocation;
         $this->sMediaQuery = $sMediaQuery;
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
         $this->aComments = [];
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * @param URL $oLocation
      *
diff --git a/src/Rule/Rule.php b/src/Rule/Rule.php
index 037132e3..e358d93f 100644
--- a/src/Rule/Rule.php
+++ b/src/Rule/Rule.php
@@ -8,6 +8,8 @@
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\UnexpectedEOFException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Value\RuleValueList;
 use Sabberworm\CSS\Value\Value;
@@ -17,8 +19,10 @@
  *
  * In CSS, `Rule`s are expressed as follows: “key: value[0][0] value[0][1], value[1][0] value[1][1];”
  */
-class Rule implements Renderable, Commentable
+class Rule implements Commentable, Positionable, Renderable
 {
+    use Position;
+
     /**
      * @var string
      */
@@ -39,18 +43,6 @@ class Rule implements Renderable, Commentable
      */
     private $aIeHack;
 
-    /**
-     * @var int
-     */
-    protected $iLineNo;
-
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iColNo;
-
     /**
      * @var array<array-key, Comment>
      *
@@ -69,8 +61,7 @@ public function __construct($sRule, $iLineNo = 0, $iColNo = 0)
         $this->mValue = null;
         $this->bIsImportant = false;
         $this->aIeHack = [];
-        $this->iLineNo = $iLineNo;
-        $this->iColNo = $iColNo;
+        $this->setPosition($iLineNo, $iColNo);
         $this->aComments = [];
     }
 
@@ -142,34 +133,6 @@ private static function listDelimiterForRule($sRule)
         }
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
-    /**
-     * @return int
-     */
-    public function getColNo()
-    {
-        return $this->iColNo;
-    }
-
-    /**
-     * @param int $iLine
-     * @param int $iColumn
-     *
-     * @return void
-     */
-    public function setPosition($iLine, $iColumn)
-    {
-        $this->iColNo = $iColumn;
-        $this->iLineNo = $iLine;
-    }
-
     /**
      * @param string $sRule
      *
@@ -295,7 +258,7 @@ public function addValue($mValue, $sType = ' ')
         }
         if (!$this->mValue instanceof RuleValueList || $this->mValue->getListSeparator() !== $sType) {
             $mCurrentValue = $this->mValue;
-            $this->mValue = new RuleValueList($sType, $this->iLineNo);
+            $this->mValue = new RuleValueList($sType, $this->getLineNumber());
             if ($mCurrentValue) {
                 $this->mValue->addListComponent($mCurrentValue);
             }
diff --git a/src/RuleSet/DeclarationBlock.php b/src/RuleSet/DeclarationBlock.php
index 3b6c8775..9cc14ebf 100644
--- a/src/RuleSet/DeclarationBlock.php
+++ b/src/RuleSet/DeclarationBlock.php
@@ -434,8 +434,8 @@ public function expandBackgroundShorthand()
             'background-repeat' => ['repeat'],
             'background-attachment' => ['scroll'],
             'background-position' => [
-                new Size(0, '%', false, $this->iLineNo),
-                new Size(0, '%', false, $this->iLineNo),
+                new Size(0, '%', false, $this->getLineNo()),
+                new Size(0, '%', false, $this->getLineNo()),
             ],
         ];
         $mRuleValue = $oRule->getValue();
@@ -801,7 +801,7 @@ public function createFontShorthand()
                 $aLHValues = $mRuleValue->getListComponents();
             }
             if ($aLHValues[0] !== 'normal') {
-                $val = new RuleValueList('/', $this->iLineNo);
+                $val = new RuleValueList('/', $this->getLineNo());
                 $val->addListComponent($aFSValues[0]);
                 $val->addListComponent($aLHValues[0]);
                 $oNewRule->addValue($val);
@@ -817,7 +817,7 @@ public function createFontShorthand()
         } else {
             $aFFValues = $mRuleValue->getListComponents();
         }
-        $oFFValue = new RuleValueList(',', $this->iLineNo);
+        $oFFValue = new RuleValueList(',', $this->getLineNo());
         $oFFValue->setListComponents($aFFValues);
         $oNewRule->addValue($oFFValue);
 
@@ -851,7 +851,10 @@ public function render($oOutputFormat)
         $sResult = $oOutputFormat->comments($this);
         if (count($this->aSelectors) === 0) {
             // If all the selectors have been removed, this declaration block becomes invalid
-            throw new OutputException("Attempt to print declaration block with missing selector", $this->iLineNo);
+            throw new OutputException(
+                'Attempt to print declaration block with missing selector',
+                $this->getLineNumber()
+            );
         }
         $sResult .= $oOutputFormat->sBeforeDeclarationBlock;
         $sResult .= $oOutputFormat->implode(
diff --git a/src/RuleSet/RuleSet.php b/src/RuleSet/RuleSet.php
index c0843389..85b94f26 100644
--- a/src/RuleSet/RuleSet.php
+++ b/src/RuleSet/RuleSet.php
@@ -8,6 +8,8 @@
 use Sabberworm\CSS\Parsing\ParserState;
 use Sabberworm\CSS\Parsing\UnexpectedEOFException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Renderable;
 use Sabberworm\CSS\Rule\Rule;
 
@@ -20,8 +22,10 @@
  * If you want to manipulate a `RuleSet`, use the methods `addRule(Rule $rule)`, `getRules()` and `removeRule($rule)`
  * (which accepts either a `Rule` or a rule name; optionally suffixed by a dash to remove all related rules).
  */
-abstract class RuleSet implements Renderable, Commentable
+abstract class RuleSet implements Commentable, Positionable, Renderable
 {
+    use Position;
+
     /**
      * the rules in this rule set, using the property name as the key,
      * with potentially multiple rules per property name.
@@ -30,13 +34,6 @@ abstract class RuleSet implements Renderable, Commentable
      */
     private $aRules;
 
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iLineNo;
-
     /**
      * @var array<array-key, Comment>
      *
@@ -50,7 +47,7 @@ abstract class RuleSet implements Renderable, Commentable
     public function __construct($iLineNo = 0)
     {
         $this->aRules = [];
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
         $this->aComments = [];
     }
 
@@ -102,14 +99,6 @@ public static function parseRuleSet(ParserState $oParserState, RuleSet $oRuleSet
         $oParserState->consume('}');
     }
 
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
-
     /**
      * @param Rule|null $oSibling
      *
diff --git a/src/Value/CSSFunction.php b/src/Value/CSSFunction.php
index fcf641d5..703f6658 100644
--- a/src/Value/CSSFunction.php
+++ b/src/Value/CSSFunction.php
@@ -34,7 +34,7 @@ public function __construct($sName, $aArguments, $sSeparator = ',', $iLineNo = 0
             $aArguments = $aArguments->getListComponents();
         }
         $this->sName = $sName;
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo); // TODO: redundant?
         parent::__construct($aArguments, $sSeparator, $iLineNo);
     }
 
diff --git a/src/Value/Value.php b/src/Value/Value.php
index 3816289d..beb74464 100644
--- a/src/Value/Value.php
+++ b/src/Value/Value.php
@@ -6,27 +6,24 @@
 use Sabberworm\CSS\Parsing\SourceException;
 use Sabberworm\CSS\Parsing\UnexpectedEOFException;
 use Sabberworm\CSS\Parsing\UnexpectedTokenException;
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
 use Sabberworm\CSS\Renderable;
 
 /**
  * Abstract base class for specific classes of CSS values: `Size`, `Color`, `CSSString` and `URL`, and another
  * abstract subclass `ValueList`.
  */
-abstract class Value implements Renderable
+abstract class Value implements Positionable, Renderable
 {
-    /**
-     * @var int
-     *
-     * @internal since 8.8.0
-     */
-    protected $iLineNo;
+    use Position;
 
     /**
      * @param int $iLineNo
      */
     public function __construct($iLineNo = 0)
     {
-        $this->iLineNo = $iLineNo;
+        $this->setPosition($iLineNo);
     }
 
     /**
@@ -218,12 +215,4 @@ private static function parseUnicodeRangeValue(ParserState $oParserState)
         } while (strlen($sRange) < $iCodepointMaxLength && preg_match("/[A-Fa-f0-9\?-]/", $oParserState->peek()));
         return "U+{$sRange}";
     }
-
-    /**
-     * @return int
-     */
-    public function getLineNo()
-    {
-        return $this->iLineNo;
-    }
 }
diff --git a/tests/Unit/Position/Fixtures/ConcretePosition.php b/tests/Unit/Position/Fixtures/ConcretePosition.php
new file mode 100644
index 00000000..0db38706
--- /dev/null
+++ b/tests/Unit/Position/Fixtures/ConcretePosition.php
@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Position\Fixtures;
+
+use Sabberworm\CSS\Position\Position;
+use Sabberworm\CSS\Position\Positionable;
+
+final class ConcretePosition implements Positionable
+{
+    use Position;
+}
diff --git a/tests/Unit/Position/PositionTest.php b/tests/Unit/Position/PositionTest.php
new file mode 100644
index 00000000..86222880
--- /dev/null
+++ b/tests/Unit/Position/PositionTest.php
@@ -0,0 +1,232 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\Unit\Position;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Tests\Unit\Position\Fixtures\ConcretePosition;
+use TRegx\DataProvider\DataProviders;
+
+/**
+ * @covers \Sabberworm\CSS\Position\Position
+ */
+final class PositionTest extends TestCase
+{
+    /**
+     * @var ConcretePosition
+     */
+    private $subject;
+
+    /**
+     * The method signature of `setUp()` is not compatible with all PHP and PHPUnit versions supported.
+     */
+    protected function doSetUp()
+    {
+        $this->subject = new ConcretePosition();
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNumberInitiallyReturnsNull()
+    {
+        $this->doSetUp();
+
+        self::assertNull($this->subject->getLineNumber());
+    }
+
+    /**
+     * @test
+     */
+    public function getColumnNumberInitiallyReturnsNull()
+    {
+        $this->doSetUp();
+
+        self::assertNull($this->subject->getColumnNumber());
+    }
+
+    /**
+     * @return array<non-empty-string, array{0: int<1, max>}>
+     */
+    public function provideLineNumber()
+    {
+        return [
+            'line 1' => [1],
+            'line 42' => [42],
+        ];
+    }
+
+    /**
+     * @test
+     *
+     * @param int<1, max> $lineNumber
+     *
+     * @dataProvider provideLineNumber
+     */
+    public function setPositionOnVirginSetsLineNumber($lineNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition($lineNumber);
+
+        self::assertSame($lineNumber, $this->subject->getLineNumber());
+    }
+
+    /**
+     * @test
+     *
+     * @param int<1, max> $lineNumber
+     *
+     * @dataProvider provideLineNumber
+     */
+    public function setPositionSetsNewLineNumber($lineNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(99);
+
+        $this->subject->setPosition($lineNumber);
+
+        self::assertSame($lineNumber, $this->subject->getLineNumber());
+    }
+
+    /**
+     * @test
+     */
+    public function setPositionWithNullClearsLineNumber()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(99);
+
+        $this->subject->setPosition(null);
+
+        self::assertNull($this->subject->getLineNumber());
+    }
+
+    /**
+     * @return array<non-empty-string, array{0: int<0, max>}>
+     */
+    public function provideColumnNumber()
+    {
+        return [
+            'column 0' => [0],
+            'column 14' => [14],
+            'column 39' => [39],
+        ];
+    }
+
+    /**
+     * @test
+     *
+     * @param int<0, max> $columnNumber
+     *
+     * @dataProvider provideColumnNumber
+     */
+    public function setPositionOnVirginSetsColumnNumber($columnNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, $columnNumber);
+
+        self::assertSame($columnNumber, $this->subject->getColumnNumber());
+    }
+
+    /**
+     * @test
+     *
+     * @param int $columnNumber
+     *
+     * @dataProvider provideColumnNumber
+     */
+    public function setPositionSetsNewColumnNumber($columnNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, 99);
+
+        $this->subject->setPosition(2, $columnNumber);
+
+        self::assertSame($columnNumber, $this->subject->getColumnNumber());
+    }
+
+    /**
+     * @test
+     */
+    public function setPositionWithoutColumnNumberClearsColumnNumber()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, 99);
+
+        $this->subject->setPosition(2);
+
+        self::assertNull($this->subject->getColumnNumber());
+    }
+
+    /**
+     * @test
+     */
+    public function setPositionWithNullForColumnNumberClearsColumnNumber()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, 99);
+
+        $this->subject->setPosition(2, null);
+
+        self::assertNull($this->subject->getColumnNumber());
+    }
+
+    /**
+     * @return array<non-empty-string, array{0: int<1, max>, 1: int<0, max>}>
+     */
+    public function provideLineAndColumnNumber()
+    {
+        if (!\class_exists(DataProviders::class)) {
+            self::markTestSkipped('`DataProviders` class is not available');
+            return [];
+        }
+
+        return DataProviders::cross($this->provideLineNumber(), $this->provideColumnNumber());
+    }
+
+    /**
+     * @test
+     *
+     * @param int $lineNumber
+     * @param int $columnNumber
+     *
+     * @dataProvider provideLineAndColumnNumber
+     */
+    public function setPositionOnVirginSetsLineAndColumnNumber($lineNumber, $columnNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition($lineNumber, $columnNumber);
+
+        self::assertSame($lineNumber, $this->subject->getLineNumber());
+        self::assertSame($columnNumber, $this->subject->getColumnNumber());
+    }
+
+    /**
+     * @test
+     *
+     * @param int $lineNumber
+     * @param int $columnNumber
+     *
+     * @dataProvider provideLineAndColumnNumber
+     */
+    public function setPositionSetsNewLineAndColumnNumber($lineNumber, $columnNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(98, 99);
+
+        $this->subject->setPosition($lineNumber, $columnNumber);
+
+        self::assertSame($lineNumber, $this->subject->getLineNumber());
+        self::assertSame($columnNumber, $this->subject->getColumnNumber());
+    }
+}
diff --git a/tests/UnitDeprecated/Position/PositionTest.php b/tests/UnitDeprecated/Position/PositionTest.php
new file mode 100644
index 00000000..f7378e04
--- /dev/null
+++ b/tests/UnitDeprecated/Position/PositionTest.php
@@ -0,0 +1,158 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Sabberworm\CSS\Tests\UnitDeprecated\Position;
+
+use PHPUnit\Framework\TestCase;
+use Sabberworm\CSS\Tests\Unit\Position\Fixtures\ConcretePosition;
+
+/**
+ * @covers \Sabberworm\CSS\Position\Position
+ */
+final class PositionTest extends TestCase
+{
+    /**
+     * @var ConcretePosition
+     */
+    private $subject;
+
+    /**
+     * The method signature of `setUp()` is not compatible with all PHP and PHPUnit versions supported.
+     */
+    protected function doSetUp()
+    {
+        $this->subject = new ConcretePosition();
+    }
+
+    /**
+     * @return array<non-empty-string, array{0: int<1, max>}>
+     */
+    public function provideLineNumber()
+    {
+        return [
+            'line 1' => [1],
+            'line 42' => [42],
+        ];
+    }
+
+    /**
+     * @return array<non-empty-string, array{0: int<0, max>}>
+     */
+    public function provideColumnNumber()
+    {
+        return [
+            'column 0' => [0],
+            'column 14' => [14],
+            'column 39' => [39],
+        ];
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNoInitiallyReturnsZero()
+    {
+        $this->doSetUp();
+
+        self::assertSame(0, $this->subject->getLineNo());
+    }
+
+    /**
+     * @test
+     *
+     * @paarm int $lineNumber
+     *
+     * @dataProvider provideLineNumber
+     */
+    public function getLineNoReturnsLineNumberSet($lineNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition($lineNumber);
+
+        self::assertSame($lineNumber, $this->subject->getLineNo());
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNoReturnsZeroAfterLineNumberCleared()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(99);
+
+        $this->subject->setPosition(null);
+
+        self::assertSame(0, $this->subject->getLineNo());
+    }
+
+    /**
+     * @test
+     */
+    public function getColNoInitiallyReturnsZero()
+    {
+        $this->doSetUp();
+
+        self::assertSame(0, $this->subject->getColNo());
+    }
+
+    /**
+     * @test
+     *
+     * @param int $columnNumber
+     *
+     * @dataProvider provideColumnNumber
+     */
+    public function getColNoReturnsColumnNumberSet($columnNumber)
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, $columnNumber);
+
+        self::assertSame($columnNumber, $this->subject->getColNo());
+    }
+
+    /**
+     * @test
+     */
+    public function getColNoReturnsZeroAfterColumnNumberCleared()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(1, 99);
+
+        $this->subject->setPosition(2);
+
+        self::assertSame(0, $this->subject->getColNo());
+    }
+
+    /**
+     * @test
+     */
+    public function setPositionWithZeroClearsLineNumber()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(99);
+
+        $this->subject->setPosition(0);
+
+        self::assertNull($this->subject->getLineNumber());
+    }
+
+    /**
+     * @test
+     */
+    public function getLineNoAfterSetPositionWithZeroReturnsZero()
+    {
+        $this->doSetUp();
+
+        $this->subject->setPosition(99);
+
+        $this->subject->setPosition(0);
+
+        self::assertSame(0, $this->subject->getLineNo());
+    }
+}