i cant work rune to only knight

[tibiek]

i have look

<rune name="Mega Uh" id="2297" allowfaruse="1" charges="1" lvl="300" maglv="6" exhaustion="1000" aggressive="0" needtarget="1" blocktype="solid" event="script" value="healing/mega uh.lua"/>
<vocation id="4"/>
<vocation id="8" showInDescription="0"/>

i need only knight used this rune how?

 

[Cykotitan]

	<rune name="Mega Uh" id="2297" allowfaruse="1" charges="1" lvl="300" maglv="6" exhaustion="1000" aggressive="0" needtarget="1" blocktype="solid" event="script" value="healing/mega uh.lua">
		<vocation id="4"/>
		<vocation id="8" showInDescription="0"/>
	</rune>

 

[tibiek]

thank youu Cykotitan ;** xDD