A TC field can be used to mark text you want to include in your TOC.
Besides the TOC field, there is another field that can be used in an automatic TOC: the TC field. The TC field is another way, along with heading styles, custom styles, or outline levels, that you can mark the text you want to include in the TOC.
So when would you use a TC field? Use it when you don't want to format the TOC entry by using a heading style, custom style, or outline level, but you still want to include the text in the TOC. Or use it when you want to include text from the middle of a sentence or paragraph, such as a long title or heading that would be awkward in the TOC. You can use the TC field to capture a portion of the title or heading and then only that portion will be included in the TOC.
Another great time to use TC fields is when you've inherited a poorly formatted document that needs a TOC; it will be quicker to add TC fields than to reformat the document with heading styles.
You'll get to practice setting up a document using TC fields and then building a TOC using them.
As with TOC fields, you can see all the TC switches by clicking Quick Parts in the Text group on the Insert tab, and then clicking Field. Select the Index and Tables category and the TC field name. Then click Field Codes and then Options to open the Field Options dialog box.