man page: document when substitutions are applied for RUN and other keys

2 files changed, 12 insertions, 5 deletions

diff --git a/docs/udev.xml b/docs/udev.xml
index 7e29077977..e0542a6be1 100644
--- a/docs/udev.xml
+++ b/docs/udev.xml
@@ -353,8 +353,12 @@
           </variablelist>
 
           <para>The <option>NAME</option>, <option>SYMLINK</option>, <option>PROGRAM</option>,
-          <option>OWNER</option>  and  <option>GROUP</option>  fields  support  simple
-          printf-like string substitutions:</para>
+          <option>OWNER</option>, <option>GROUP</option>  and  <option>RUN</option>
+          fields support simple printf-like string substitutions. The <option>RUN</option>
+          format chars gets applied after all rules have been processed, right before the program
+          is executed. It allows the use of the complete environment set by earlier matching
+          rules. For all other fields, substitutions are applied while the individual rule is
+          being processed. The available substitutions are:</para>
           <variablelist>
             <varlistentry>
               <term><option>$kernel</option>, <option>%k</option></term>
diff --git a/udev.7 b/udev.7
index a7e2f5a4e7..711bd0861b 100644
--- a/udev.7
+++ b/udev.7
@@ -164,10 +164,13 @@ The
 \fBNAME\fR,
 \fBSYMLINK\fR,
 \fBPROGRAM\fR,
-\fBOWNER\fR
-and
+\fBOWNER\fR,
 \fBGROUP\fR
-fields support simple printf\-like string substitutions:
+and
+\fBRUN\fR
+fields support simple printf\-like string substitutions. The
+\fBRUN\fR
+format chars gets applied after all rules have been processed, right before the program is executed. It allows the use of the complete environment set by earlier matching rules. For all other fields, substitutions are applied while the individual rule is being processed. The available substitutions are:
 .TP
 \fB$kernel\fR, \fB%k\fR
 The kernel name for this device.