diff --git a/README.md b/README.md
index dd5c934..4c0d0bf 100644
--- a/README.md
+++ b/README.md
@@ -37,8 +37,15 @@ If EPUBCheck is installed locally, it will be run alongside the Go tests. To ins
 1. Download and extract EPUBCheck in the root directory of this project, e.g.
 
    ```
-   wget https://github.com/IDPF/epubcheck/releases/download/v4.2.5/epubcheck-4.2.5.zip
-   unzip epubcheck-4.2.5.zip
+   wget https://github.com/IDPF/epubcheck/releases/download/v5.1.0/epubcheck-5.1.0.zip
+   unzip epubcheck-5.1.0.zip
+   ```
+
+   You can use this command to download and extract the latest versions of EPUBCheck (recommended).
+
+   ```
+   curl -s https://api.github.com/repos/w3c/epubcheck/releases/latest | awk -F': "' '/browser_download_url/ && /epubcheck/ {gsub(/"$/, "", $2); print $2}' | xargs curl -Lo epubcheck.zip
+   unzip epubcheck.zip
    ```
 
 If you do not wish to install EPUBCheck locally, you can manually validate the EPUB:
diff --git a/epub.go b/epub.go
index 35d4a43..95a3daa 100644
--- a/epub.go
+++ b/epub.go
@@ -31,6 +31,8 @@ Basic usage:
 package epub
 
 import (
+	"bytes"
+	"encoding/xml"
 	"fmt"
 	"io/fs"
 	"log"
@@ -156,9 +158,10 @@ type epubCover struct {
 }
 
 type epubSection struct {
-	filename string
-	xhtml    *xhtml
-	children []*epubSection
+	filename   string
+	xhtml      *xhtml
+	children   []*epubSection
+	properties string
 }
 
 // NewEpub returns a new Epub.
@@ -377,9 +380,10 @@ func (e *Epub) addSection(parentFilename string, body string, sectionTitle strin
 	}
 
 	s := &epubSection{
-		filename: internalFilename,
-		xhtml:    x,
-		children: nil,
+		filename:   internalFilename,
+		xhtml:      x,
+		children:   nil,
+		properties: propertiesFromBody(body),
 	}
 
 	// section have parentIndex -1 and subsection have parrentindex != -1
@@ -397,6 +401,40 @@ func (e *Epub) addSection(parentFilename string, body string, sectionTitle strin
 	return internalFilename, nil
 }
 
+// supports mathml, svg, scripted
+// does not support remote-sources, switch (deprecated)
+func propertiesFromBody(body string) string {
+	prop := map[string]bool{}
+
+	decoder := xml.NewDecoder(bytes.NewBufferString(body))
+	for {
+		t, _ := decoder.Token()
+		if t == nil {
+			break
+		}
+		switch se := t.(type) {
+		case xml.StartElement:
+			switch strings.ToUpper(se.Name.Local) {
+			case "SVG":
+				prop["svg"] = true
+			case "MATH":
+				if se.Name.Space == "http://www.w3.org/1998/Math/MathML" {
+					prop["mathml"] = true
+				}
+			case "SCRIPT", "FORM":
+				prop["scripted"] = true
+			}
+		default:
+		}
+	}
+
+	ret := []string{}
+	for k := range prop {
+		ret = append(ret, k)
+	}
+	return strings.Join(ret, " ")
+}
+
 // Author returns the author of the EPUB.
 func (e *Epub) Author() string {
 	return e.author
diff --git a/epub_test.go b/epub_test.go
index f2ab888..0f25e85 100644
--- a/epub_test.go
+++ b/epub_test.go
@@ -1480,3 +1480,56 @@ func TestAddSubSectionWithCustomFilename(t *testing.T) {
 
 	cleanup(testEpubFilename, tempDir)
 }
+
+func TestSectionProperties(t *testing.T) {
+	e, err := NewEpub(testEpubTitle)
+	if err != nil {
+		t.Error(err)
+	}
+
+	_, err = e.AddSection("<h1>Section 1</h1>", "Section 1", "section0001.xhtml", "")
+	if err != nil {
+		t.Errorf("Error adding section: %s", err)
+	}
+
+	_, err = e.AddSection("<h1>Section 2</h1><p><svg xmlns='http://www.w3.org/2000/svg'></svg></p>", "Section 2", "section0002.xhtml", "")
+	if err != nil {
+		t.Errorf("Error adding section: %s", err)
+	}
+
+	_, err = e.AddSection("<h1>Section 3</h1><p><script></script></p>", "Section 3", "section0003.xhtml", "")
+	if err != nil {
+		t.Errorf("Error adding section: %s", err)
+	}
+
+	_, err = e.AddSection(`<h1>Section 4</h1><form></form>`, "Section 4", "section0004.xhtml", "")
+	if err != nil {
+		t.Errorf("Error adding section: %s", err)
+	}
+
+	_, err = e.AddSection("<h1>Section 5</h1><p><math xmlns='http://www.w3.org/1998/Math/MathML'></math></p>", "Section 5", "section0005.xhtml", "")
+	if err != nil {
+		t.Errorf("Error adding section: %s", err)
+	}
+
+	tempDir := writeAndExtractEpub(t, e, testEpubFilename)
+
+	output, err := validateEpub(t, testEpubFilename)
+	if err != nil {
+		t.Errorf("EPUB validation failed")
+	}
+
+	// Always print the output so we can see warnings as well
+	if output != nil {
+		fmt.Println(string(output))
+	}
+	if doCleanup {
+		cleanup(testEpubFilename, tempDir)
+	} else {
+		// Always remove the files in tempDir; they can still be extracted from the test epub as needed
+		err := filesystem.RemoveAll(tempDir)
+		if err != nil {
+			log.Print("Error removing temp directory: %w", err)
+		}
+	}
+}
diff --git a/toc.go b/toc.go
index 8371478..9e0acb5 100644
--- a/toc.go
+++ b/toc.go
@@ -4,6 +4,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"log"
+	"path"
 	"path/filepath"
 	"regexp"
 	"strconv"
@@ -174,7 +175,7 @@ func (t *toc) addSubSection(parent string, index int, title string, relativePath
 		t.ncxXML.NavMap = append(t.ncxXML.NavMap, np)
 	} else {
 
-		parentRelativePath := filepath.Join(xhtmlFolderName, parent)
+		parentRelativePath := path.Join(xhtmlFolderName, parent)
 
 		l := &tocNavItem{
 			A: tocNavLink{
diff --git a/write.go b/write.go
index eb9b0a0..637c406 100644
--- a/write.go
+++ b/write.go
@@ -485,7 +485,7 @@ func writeSections(rootEpubDir string, e *Epub, sections []*epubSection, parentf
 		if section.filename != e.cover.xhtmlFilename {
 			e.pkg.addToSpine(section.filename)
 		}
-		e.pkg.addToManifest(section.filename, relativePath, mediaTypeXhtml, "")
+		e.pkg.addToManifest(section.filename, relativePath, mediaTypeXhtml, section.properties)
 		if parentfilename[section.filename] == "-1" && section.filename != e.cover.xhtmlFilename {
 			j := filenamelist[section.filename]
 			e.toc.addSubSection("-1", j, section.xhtml.Title(), relativePath)