add TAG= to improve event filtering and device enumeration

[elogind.git] / udev / udev.xml

diff --git a/udev/udev.xml b/udev/udev.xml
index 192a6f1238d806c642322c774d65e469e7f6ad7e..842fd5d52aa8f6d3fdd17a1495fd95c3cbfff9c7 100644 (file)
--- a/udev/udev.xml
+++ b/udev/udev.xml
@@ -348,6 +348,19 @@
               </listitem>
             </varlistentry>
 
+            <varlistentry>
+              <term><option>TAG</option></term>
+              <listitem>
+                <para>Attach a tag to a device. This is used to filter events for users
+                of libudev's monitor functionality, or to enumerate a group of tagged
+                devices. The implementation can only work efficiently if only a few
+                tags are attached to a device. It is only meant to be used in
+                contexts with specific device filter requirements, and not as a
+                general-purpose flag. Excessive use might result in inefficient event
+                handling.</para>
+              </listitem>
+            </varlistentry>
+
             <varlistentry>
               <term><option>RUN</option></term>
               <listitem>