Docs: clarify quoting for $pipe_addresses

The texinfo output version has single-quotes round a variable,
so the sentence saying "precisely the text" was difficult to
interpret.

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c53a392a4fb4e6eadc0fe078d18c665598944d6a..4d4bab7c256c1e3bf79562ced7050b4b76f7e30e 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -23581,7 +23581,8 @@ command = /bin/sh -c ${lookup{$local_part}lsearch{/some/file}}
 .cindex "filter" "transport filter"
 .vindex "&$pipe_addresses$&"
 Special handling takes place when an argument consists of precisely the text
-&`$pipe_addresses`&. This is not a general expansion variable; the only
+&`$pipe_addresses`& (no quotes).
+This is not a general expansion variable; the only
 place this string is recognized is when it appears as an argument for a pipe or
 transport filter command. It causes each address that is being handled to be
 inserted in the argument list at that point &'as a separate argument'&. This