Docs: tweak local_scan chapter

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 25f97535ad06b3a255f5cd23350dbe05727ab750..f7002b9fe7893685b88d73e2c87edd4b4294d491 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -4510,6 +4510,10 @@ stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
 every domain. Addresses are routed, local deliveries happen, but no remote
 transports are run.
 
+.new
+Performance will be best if the &%queue_run_in_order%& option is false.
+.wen
+
 .cindex "hints database" "remembering routing"
 The hints database that remembers which messages are waiting for specific hosts
 is updated, as if delivery to those hosts had been deferred. After this is
@@ -18650,15 +18654,19 @@ avoided. The &%repeat_use%& option of the &%redirect%& router may be of help.
 This option specifies a list of text headers,
 colon-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&),
 that is associated with any addresses that are accepted by the router.
-Each item is separately expanded, at routing time.  However, this
-option has no effect when an address is just being verified. The way in which
+However, the option has no effect when an address is just being verified.
+Each list item is separately expanded, at transport time.
+.new
+If an item ends in *, it will match any header with the given prefix.
+.wen
+The way in which
 the text is used to remove header lines at transport time is described in
 section &<<SECTheadersaddrem>>&. Header lines are not actually removed until
 the message is in the process of being transported. This means that references
 to header lines in string expansions in the transport's configuration still
 &"see"& the original header lines.
 
-The &%headers_remove%& option is expanded after &%errors_to%& and
+The &%headers_remove%& option is handled after &%errors_to%& and
 &%headers_add%&, but before &%transport%&. If an item expansion is forced to fail,
 the item has no effect. Other expansion failures are treated as configuration
 errors.
@@ -21837,15 +21845,21 @@ checked, since this option does not automatically suppress them.
 .option headers_remove transports list&!! unset
 .cindex "header lines" "removing"
 .cindex "transport" "header lines; removing"
-This option specifies a list of header names,
-colon-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&);
-these headers are omitted from the message as it is transported, as described
-in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
-routers.
+This option specifies a list of text headers,
+colon-separated (by default, changeable in the usual way &<<SECTlistsepchange>>&),
+to be removed from the message.
+However, the option has no effect when an address is just being verified.
 Each list item is separately expanded.
 If the result of the expansion is an empty string, or if the expansion
 is forced to fail, no action is taken. Other expansion failures are treated as
 errors and cause the delivery to be deferred.
+.new
+If an item ends in *, it will match any header with the given prefix.
+.wen
+
+Matching headers are omitted from the message as it is transported, as described
+in section &<<SECTheadersaddrem>>&. Header removal can also be specified by
+routers.
 
 Unlike most options, &%headers_remove%& can be specified multiple times
 for a transport; all listed headers are removed.
@@ -33893,13 +33907,14 @@ in &_Local/Makefile_& (see section &<<SECTconoptloc>>& below).
 .cindex &%dlfunc%& "API description"
 You must include this line near the start of your code:
 .code
+#define LOCAL_SCAN
 #include "local_scan.h"
 .endd
 This header file defines a number of variables and other values, and the
 prototype for the function itself. Exim is coded to use unsigned char values
 almost exclusively, and one of the things this header defines is a shorthand
 for &`unsigned char`& called &`uschar`&.
-It also contains the following macro definitions, to simplify casting character
+It also makes available the following macro definitions, to simplify casting character
 strings and pointers to character strings:
 .code
 #define CS   (char *)