X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=blobdiff_plain;f=README;h=14cc5420f4783f5f4568c73e58eab1c48f5759f9;hp=0b84a0ec35dcfd6aec0c08736bd3f9b028b25b91;hb=9178f4c13177c6436d08182e1649d8476b4c3b8a;hpb=80ebf1020232f0aa081f18b3b5fc432bd81a5544

diff --git a/README b/README
index 0b84a0e..14cc542 100644
--- a/README
+++ b/README
@@ -205,6 +205,10 @@ Dollar doubling and macro assistance
 &$-		Stops dollar-doubling
 	Both are idempotent and local to the file or context.
 
+This is useful both for make macrology involving $(eval ...), and
+possibly for helping write complicated recipes involving shell
+variables, inline Perl code, etc.
+
 Sometimes we will show $'s being doubled inside another construct.
 This means the content of the construct is $-doubled: $-doubling is
 locally enabled, and restored afterwards.
@@ -233,8 +237,8 @@ $	=>	$$	including $'s produced by other
 			 &-expansions not mentioned here
 
 &\$	=>	$
-&$(	=>	$(
-&$NN	=>	$(NN)	where N are digits
+&$(	=>	${	(expands to { } so it is useable for shell too)
+&$NN	=>	${NN}	where N are digits
 
 A few contexts do not support $-doubling, such as directive arguments
 or places where this might imply $-quadrupling.  (There is no way to