er, no. ${foo} has been the standard way to disambiguate variables for a long time now and was independent of regex. Mostly used for strings, aside from this as in: print "${Foo}bar" and similar, also used for references, so called "soft" refs in the form of ${"foo"} and hard refs in the form of $x=\$foo; ${$x} Also works with the various other sigils, $%@.