Example
default
btn_ggPrimary2
btn_ggPrimary3
btn_ggPrimary4
btn_ggSecondary1
btn_ggSecondary2
Markup
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">default</div>
   <div class="grid-2 layout_center">
     <a class="btn btn_narrow btn_shorter">default</a>
   </div>
 </div>
<!--
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggPrimary1</div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary1Darker btn_narrow btn_shorter">darker</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary1Dark btn_narrow btn_shorter">dark</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary1 btn_narrow btn_shorter">normal</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary1Light btn_narrow btn_shorter">light</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary1Lighter btn_narrow btn_shorter">lighter</a>
   </div>
 </div>
-->
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggPrimary2</div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary2Darker btn_narrow btn_shorter">darker</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary2Dark btn_narrow btn_shorter">dark</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary2 btn_narrow btn_shorter">normal</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary2Light btn_narrow btn_shorter">light</a>
   </div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggPrimary2Lighter btn_narrow btn_shorter">lighter</a>
     -->
   </div>
 </div>
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggPrimary3</div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggPrimary3Darker btn_narrow btn_shorter">darker</a>
     -->
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary3Dark btn_narrow btn_shorter">dark</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary3 btn_narrow btn_shorter">normal</a>
   </div>
   <div class="grid-2 layout_center">
   <!--
     <a class="btn btn_ggPrimary3Light btn_narrow btn_shorter">light</a>
   -->
   </div>
   <div class="grid-2 layout_center">
   <!--
     <a class="btn btn_ggPrimary3Lighter btn_narrow btn_shorter">lighter</a>
   -->
   </div>
 </div>
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggPrimary4</div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary4Darker btn_narrow btn_shorter">darker</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary4Dark btn_narrow btn_shorter">dark</a>
   </div>
   <!--
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary4 btn_narrow btn_shorter">normal</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary4Light btn_narrow btn_shorter">light</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggPrimary4Lighter btn_narrow btn_shorter">lighter</a>
   </div>
 -->
 </div>
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggSecondary1</div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggSecondary1Darker btn_narrow btn_shorter">darker</a>
     -->
   </div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggSecondary1Dark btn_narrow btn_shorter">dark</a>
     -->
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary1 btn_narrow btn_shorter">normal</a>
   </div>
   <!--
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary1Light btn_narrow btn_shorter">light</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary1Lighter btn_narrow btn_shorter">lighter</a>
   </div>
 -->
 </div>
 <div class="grid-12 grid-parent layout_centerVertical">
   <div class="grid-2 text_fontSizeSmaller layout_center">btn_ggSecondary2</div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggSecondary2Darker btn_narrow btn_shorter">darker</a>
     -->
   </div>
   <div class="grid-2 layout_center">
     <!--
     <a class="btn btn_ggSecondary2Dark btn_narrow btn_shorter">dark</a>
     -->
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary2 btn_narrow btn_shorter">normal</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary2Light btn_narrow btn_shorter">light</a>
   </div>
   <div class="grid-2 layout_center">
     <a class="btn btn_ggSecondary2Lighter btn_narrow btn_shorter">lighter</a>
   </div>
 </div>
Source: modules/05_user_interface/buttons.less, line 168