--- a/relpipe-data/specification.xml	Fri Nov 30 16:43:11 2018 +0100
+++ b/relpipe-data/specification.xml	Fri Nov 30 16:57:48 2018 +0100
@@ -56,6 +56,38 @@
 		<h2>Tools</h2>
 		
 		<h3>relpipe-in-cli</h3>
+		<p>
+			A tool that generates a single relation. I we want more relations in a single stream, we just call this command multiple times:
+		</p>
+		
+		<m:pre jazyk="bash"><![CDATA[
+(relpipe-in-cli ... ; relpipe-in-cli ... ; relpipe-in-cli ... ) | relpipe-out-tabular
+]]></m:pre>
+
+		<p>Or concatenate several files or do a combination of both files and commands.</p>
+		
+		<p>This command accept these arguments:</p>
+		
+		<ul>
+			<li>relation name</li>
+			<li>attribute count</li>
+			<li>names of attributes</li>
+			<li>types of attributes</li>
+			<li>attribute values</li>
+		</ul>
+		
+		<p>
+			These data might be passed as CLI arguments on the command line or as null-byte (<code>\0</code>) separated list of values on STDIN.
+			Both ways can be combined e.g. pass relation name and metadata as CLI arguments and the data on STDIN.
+			The tool simply starts with CLI arguments (if any) and continues with values from STDIN (if any).
+		</p>
+		
+		<p>
+			This tool is a good entry point to the <m:name/> world because it requires no programming and construction of the argument list or <code>\0</code> separated list can be done in any language or environment.
+			Tools like <code>perl</code> or <code>tr</code> can convert almost any data to this form and pass it to <code>relpipe-in-cli</code>.
+		</p>
+		
+		
 		<h3>relpipe-in-fstab</h3>
 		<h3>relpipe-out-tabular</h3>
 		<h3>relpipe-out-xml</h3>