{{NOTOC}} is a template which essentially does the opposite of {{big toc}}: when placed on a page, no table of contents (or TOC) will appear at all.
This is useful mostly on crew pages, where there are many short sections for the crew member's credits, in various jobs and positions—and a table of contents would actually interfere with the {{pcred}} listing. In general, this template should not be used outside of such a context, as page navigation should be encouraged.