Template:Part

{{#ifeq: | |

 === Part {{{number}}} === |
 {{#ifeq:   | |
    === {{{name}}} === |
    === Part {{{number}}}: {{{name}}} === 
 }}

}}

Usage: {{part|name=Name|number=Number}}, though you can omit the "Name" or "Number" parameter - The template will fail if you omit both.