diff --git a/CHANGELOG.md b/CHANGELOG.md
index 26d43b9..736c04c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,20 @@ file. The format follows
 [Keep a Changelog](https://keepachangelog.com/en/1.1.0/); versioning
 follows [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Fixed
+- The writer now emits `w:lineRule` from `ParagraphStyle::$lineSpacingRule`
+  (`auto`, `exact`, `atLeast`); it wrote `exact` whatever the rule was. The
+  reader fills the rule in, so a document with Word's usual 1.15 spacing
+  (`w:line="276" w:lineRule="auto"`) came back from read → write with lines
+  fixed at 13.8 pt, and text larger than that was clipped. An unset rule
+  still writes `exact`.
+- The writer now emits `<w:caps/>` and `<w:smallCaps/>` for
+  `RunStyle::$allCaps` / `$smallCaps`. The reader parsed them and the HTML
+  serializer wrote them, but a read → write round-trip dropped them, and a
+  heading set in small caps came back in lowercase.
+
 ## [1.15.0] — 2026-10-19
 
 ### Added
diff --git a/src/Writer/BodyXmlBuilder.php b/src/Writer/BodyXmlBuilder.php
index c8c392f..ba1fc61 100644
--- a/src/Writer/BodyXmlBuilder.php
+++ b/src/Writer/BodyXmlBuilder.php
@@ -250,7 +250,13 @@ private function renderParagraphProperties(ParagraphStyle $style, ?int $headingL
             }
             if ($style->lineSpacingTwips !== null) {
                 $attrs[] = 'w:line="'.$style->lineSpacingTwips.'"';
-                $attrs[] = 'w:lineRule="exact"';
+                // Under `auto` the number is in 240ths of a single line, under
+                // `exact`/`atLeast` it is a height in twips. An unset or unknown
+                // rule stays `exact`, as the writer wrote it before.
+                $rule = in_array($style->lineSpacingRule, ['auto', 'exact', 'atLeast'], true)
+                    ? $style->lineSpacingRule
+                    : 'exact';
+                $attrs[] = 'w:lineRule="'.$rule.'"';
             }
             $pPr .= '<w:spacing '.implode(' ', $attrs).'/>';
         }
@@ -354,6 +360,12 @@ private function renderRunProperties(RunStyle $s): string
         if ($s->italic) {
             $rPr .= '<w:i/><w:iCs/>';
         }
+        if ($s->allCaps) {
+            $rPr .= '<w:caps/>';
+        }
+        if ($s->smallCaps) {
+            $rPr .= '<w:smallCaps/>';
+        }
         if ($s->underline) {
             $rPr .= '<w:u w:val="single"/>';
         }
diff --git a/tests/Writer/CapsTest.php b/tests/Writer/CapsTest.php
new file mode 100644
index 0000000..e3ba959
--- /dev/null
+++ b/tests/Writer/CapsTest.php
@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Dskripchenko\PhpDocx\Tests\Writer;
+
+use Dskripchenko\PhpDocx\Document;
+use Dskripchenko\PhpDocx\Element\Paragraph;
+use Dskripchenko\PhpDocx\Element\Run;
+use Dskripchenko\PhpDocx\Reader\DocxReader;
+use Dskripchenko\PhpDocx\Section;
+use Dskripchenko\PhpDocx\Style\RunStyle;
+use Dskripchenko\PhpDocx\Writer\BodyXmlBuilder;
+use Dskripchenko\PhpDocx\Writer\Word2007Writer;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * RunStyle::$allCaps / $smallCaps were parsed by the reader and serialized to
+ * HTML, but the writer never emitted `<w:caps/>` / `<w:smallCaps/>`, so the
+ * formatting was lost on the way back into a DOCX.
+ */
+final class CapsTest extends TestCase
+{
+    #[Test]
+    public function writer_emits_caps_and_small_caps(): void
+    {
+        $xml = (new BodyXmlBuilder)->render([
+            new Paragraph([
+                new Run('a', new RunStyle(allCaps: true)),
+                new Run('b', new RunStyle(smallCaps: true)),
+            ]),
+        ]);
+
+        self::assertStringContainsString('<w:rPr><w:caps/></w:rPr><w:t xml:space="preserve">a</w:t>', $xml);
+        self::assertStringContainsString('<w:rPr><w:smallCaps/></w:rPr><w:t xml:space="preserve">b</w:t>', $xml);
+    }
+
+    #[Test]
+    public function caps_follow_italic_and_precede_strike(): void
+    {
+        $xml = (new BodyXmlBuilder)->render([
+            new Paragraph([new Run('x', new RunStyle(italic: true, strikethrough: true, allCaps: true, smallCaps: true))]),
+        ]);
+
+        self::assertStringContainsString('<w:i/><w:iCs/><w:caps/><w:smallCaps/>', $xml);
+        self::assertLessThan(strpos($xml, '<w:strike/>'), strpos($xml, '<w:smallCaps/>'));
+    }
+
+    #[Test]
+    public function caps_survive_write_then_read(): void
+    {
+        $bytes = (new Word2007Writer)->write(new Document(new Section([
+            new Paragraph([
+                new Run('a', new RunStyle(allCaps: true)),
+                new Run('b', new RunStyle(smallCaps: true)),
+            ]),
+        ])));
+
+        $paragraph = (new DocxReader)->read($bytes)->section->body[0];
+        self::assertInstanceOf(Paragraph::class, $paragraph);
+        [$a, $b] = $paragraph->children;
+        self::assertInstanceOf(Run::class, $a);
+        self::assertInstanceOf(Run::class, $b);
+        self::assertTrue($a->style->allCaps);
+        self::assertFalse($a->style->smallCaps);
+        self::assertTrue($b->style->smallCaps);
+        self::assertFalse($b->style->allCaps);
+    }
+}
diff --git a/tests/Writer/LineSpacingRuleTest.php b/tests/Writer/LineSpacingRuleTest.php
new file mode 100644
index 0000000..e5dadab
--- /dev/null
+++ b/tests/Writer/LineSpacingRuleTest.php
@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Dskripchenko\PhpDocx\Tests\Writer;
+
+use Dskripchenko\PhpDocx\Build\DocumentBuilder;
+use Dskripchenko\PhpDocx\Element\Paragraph;
+use Dskripchenko\PhpDocx\Element\Run;
+use Dskripchenko\PhpDocx\Reader\DocxReader;
+use Dskripchenko\PhpDocx\Style\ParagraphStyle;
+use Dskripchenko\PhpDocx\Writer\BodyXmlBuilder;
+use Dskripchenko\PhpDocx\Writer\Word2007Writer;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+/**
+ * `w:lineRule` decides what `w:line` means: under `auto` it is a fraction of
+ * single spacing (240 = single, 276 = 1.15), under `exact`/`atLeast` a height
+ * in twips. The writer used to write `exact` whatever
+ * ParagraphStyle::$lineSpacingRule said, so a document read with 1.15
+ * spacing came back with lines fixed at 13.8pt, and larger text was clipped.
+ */
+final class LineSpacingRuleTest extends TestCase
+{
+    public static function rules(): array
+    {
+        return [
+            'auto' => ['auto', 'auto'],
+            'exact' => ['exact', 'exact'],
+            'atLeast' => ['atLeast', 'atLeast'],
+            'unset keeps exact' => [null, 'exact'],
+            'unknown keeps exact' => ['bogus', 'exact'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('rules')]
+    public function writer_emits_the_rule_from_the_style(?string $rule, string $expected): void
+    {
+        $xml = (new BodyXmlBuilder)->render([
+            new Paragraph([new Run('x')], new ParagraphStyle(lineSpacingTwips: 276, lineSpacingRule: $rule)),
+        ]);
+
+        self::assertStringContainsString('<w:spacing w:line="276" w:lineRule="'.$expected.'"/>', $xml);
+    }
+
+    /**
+     * @return array<string, array{string}>
+     */
+    public static function autoSpacings(): array
+    {
+        return [
+            'explicit auto' => ['<w:spacing w:line="276" w:lineRule="auto"/>'],
+            // The schema default for a missing lineRule is auto.
+            'no lineRule' => ['<w:spacing w:line="276"/>'],
+        ];
+    }
+
+    #[Test]
+    #[DataProvider('autoSpacings')]
+    public function auto_line_spacing_survives_read_then_write(string $spacing): void
+    {
+        $source = self::docxWithBody('<w:p><w:pPr>'.$spacing.'</w:pPr><w:r><w:t>x</w:t></w:r></w:p>');
+
+        $document = (new DocxReader)->read($source);
+        $written = self::documentXml((new Word2007Writer)->write($document));
+
+        self::assertStringContainsString('<w:spacing w:line="276" w:lineRule="auto"/>', $written);
+    }
+
+    /**
+     * A package the library writes, with word/document.xml swapped for the
+     * given body, the way Word would have written it.
+     */
+    private static function docxWithBody(string $bodyInner): string
+    {
+        $bytes = DocumentBuilder::new()->paragraph('placeholder')->toBytes();
+        $tmp = (string) tempnam(sys_get_temp_dir(), 'docx-rule-');
+        file_put_contents($tmp, $bytes);
+        $zip = new \ZipArchive;
+        $zip->open($tmp);
+        $zip->addFromString(
+            'word/document.xml',
+            '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>'
+            .'<w:document xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main">'
+            .'<w:body>'.$bodyInner.'</w:body></w:document>',
+        );
+        $zip->close();
+        $out = (string) file_get_contents($tmp);
+        unlink($tmp);
+
+        return $out;
+    }
+
+    private static function documentXml(string $bytes): string
+    {
+        $tmp = (string) tempnam(sys_get_temp_dir(), 'docx-rule-');
+        file_put_contents($tmp, $bytes);
+        $zip = new \ZipArchive;
+        $zip->open($tmp);
+        $xml = (string) $zip->getFromName('word/document.xml');
+        $zip->close();
+        unlink($tmp);
+
+        return $xml;
+    }
+}