Document property expansion.
Bug: N/A
Test: N/A
Change-Id: I54b9d2d08d98d83060b54981b1c5dc9660b93e8f
diff --git a/init/README.md b/init/README.md
index d7edf21..5c2352b 100644
--- a/init/README.md
+++ b/init/README.md
@@ -10,7 +10,11 @@
whitespace from breaking text into multiple tokens. The backslash,
when it is the last character on a line, may be used for line-folding.
-Lines which start with a # (leading whitespace allowed) are comments.
+Lines which start with a `#` (leading whitespace allowed) are comments.
+
+System properties can be expanded using the syntax
+`${property.name}`. This also works in contexts where concatenation is
+required, such as `import /init.recovery.${ro.hardware}.rc`.
Actions and Services implicitly declare a new section. All commands
or options belong to the section most recently declared. Commands