See soorce fer Template:Documentation/start box2

{{documentation/start box
| preload = {{{preload|}}}   <!--Allow custom preloads-->
| heading = {{{heading|¬}}}   <!--Empty but defined means no header-->
| heading-style = {{{heading-style|}}}
| content = {{{content|}}}

| docpage = 
  {{#if: {{{1|}}}
  | {{{1|}}}
  | {{{docspace|{{NAMESPACE}}}}}:{{{template page|{{PAGENAME}}}}}/doc
  }}

| doc exist = 
  {{#ifexist: 
    {{#if: {{{1|}}}
    | {{{1|}}}   <!--Other docname fed-->
    | {{{docspace|{{NAMESPACE}}}}}:{{{template page|{{PAGENAME}}}}}/doc
    }}
  | yes
  }}

}}<noinclude>

{{pp-template}}
<!-- Add categories and interwikis to the /doc subpage, not here! -->
</noinclude>