diff --git a/documentation/content/en/books/porters-handbook/uses/_index.adoc b/documentation/content/en/books/porters-handbook/uses/_index.adoc
--- a/documentation/content/en/books/porters-handbook/uses/_index.adoc
+++ b/documentation/content/en/books/porters-handbook/uses/_index.adoc
@@ -373,6 +373,29 @@
 
 Add dependency on package:math/eigen[].
 
+[[uses-elfctl]]
+== `elfctl`
+
+Possible arguments: (none)
+
+Change an ELF binary's feature control note by setting ELF_FEATURES.
+
+[[uses-elfct-ex1]]
+.Uses=elfctl
+[example]
+====
+[.programlisting]
+....
+USES=           elfctl
+ELF_FEATURES=	featurelist:path/to/file1 \
+		featurelist:path/to/file1 \
+		featurelist:path/to/file2
+....
+
+====
+
+The format of `featurelist` is described in man:elfctl[1].  The file paths are relative to ${BUILD_WRKSRC}.
+
 [[uses-fakeroot]]
 == `fakeroot`