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
@@ -489,9 +489,12 @@
 [[uses-elfctl]]
 == `elfctl`
 
-Possible arguments: (none)
+Possible arguments: (none), `build` (default), `stage`
+
+Set ELF binary feature control notes by setting `ELF_FEATURES`.
 
-Change an ELF binary's feature control note by setting ELF_FEATURES.
+When either no argument or the `build` argument is supplied, binaries under `BUILD_WRKSRC` are operated on, and files listed in `ELF_FEATURES` are relative to `BUILD_WRKSRC`.
+When the `stage` argument is supplied, binaries under `STAGEDIR` are operated on and files listed in `ELF_FEATURES` are relative to `STAGEDIR`.
 
 [[uses-elfct-ex1]]
 .Uses=elfctl
@@ -501,13 +504,12 @@
 ....
 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}.
+The format of `featurelist` is described in man:elfctl[1].
 
 [[uses-erlang]]
 == `erlang`